PART 1

Class GASTROPODA

Subclass VETIGASTROPODA

Superfamilies

HELICINOIDEA AMPULLARIOIDEA VIVIPAROIDEA CYCLOPHOROIDEA CERITHIOIDEA VALVATOIDEA LITTORINOIDEA RISSOOIDEA


Superfamily HELICINOIDEA

Family CERESIDAE Thiele, 1925

CERESINAE Thiele, 1925; Handbuck der Zoologie, 5: 78.

CERESIDAE Thompson, 1980; Malacologia, 20: 13.

Genus Ceres Gray, 1856

Ceres Gray, 1856; Proc. Zool. Soc. London, 24: 100 — Thompson, 1980; Malacologia, 20: 17.

TYPE SPECIES — Carocolla eolina Duclus, 1834.

DISTRIBUTION — Eastern Mexico in the states of Veracruz, San Luís Potosí and Tamaulipas.

TAXONOMY — Three species are recognized.

Ceres eolina (Duclos, 1834)

Carocolla eolina Duclos, 1834; in Guérin’s Mag. Zool.: pl. 30.

Odontostoma eolina (Duclos). Pfeiffer, 1848; Monog. Helic. Viv., 1: 11.

Proserpina eolina (Duclos). Pfeiffer, 1853; Monogr. Helic. Viv., 3: 290.

Ceres eolina (Duclos). Gray, 1856; Proc. Zool. Soc. London, 24: 102 — Pfeiffer, 1856; Proc. Zool. Soc. London, 32: pl. 35: 23, 24 (shell) — Fischer & Crosse, 1892; Miss. Sci. Mex., I: 382-383; pl. 54, figs. 2-2c (shell) — Thompson, 1980; Malacologia, 24: 17.

Proserpina (Ceres) eolina (Duclos). Von Martens, 1890; Biol. Cent. Amer.: 44 — Von Martens, 1901; Biol. Cent. Amer.: 609.

TYPE LOCALITY — Cerro de Plumas [Cerro de Palmas] Sierra de Matlaquihahuitl, Veracruz.

DISTRIBUTION RECORDS — VERACRUZ: known only from the type locality.

Ceres nelsoni Dall, 1898

Ceres nelsoni Dall, 1898; Nautilus, 12: 27 — Fischer & Crosse, 1900: 668 — Dall, 1902; Proc. U. S. Nat. Mus., 24: 501; pl. 28, figs. 1, 3, 5, 8 (shell) — Solem, 1954; Nautilus, 64: 7 — Thompson, 1980; Malacologia, 24: 3-6, 17, fig. 3 (pallial organ), fig. 4 (body), figs. 5-10 (radula), figs. 12-14 (reproductive anatomy) — Correa-Sandoval, Gutierrez & Reza, 1998; Acta Zool. Mex., (73): 13 — Correa-Sandoval & Castro, 2002; Acta Zool. Mex., (86): 235.

Proserpina (Ceres) nelsoni (Dall). Von Martens, 1901; Biol. Cent. Amer.: 609.

TYPE LOCALITY — Pilitla [Xilitla], San Luís Potosí. Holotype USNM 107823.

DISTRIBUTION RECORDS.<strong — SAN LUÍS POTOSÍ: numerous localities in eastern part of state (Thompson, 1980); Xilitla, (21°22’55” N, 98°59’44” W); 6 km SW of Xilitla, 830 m alt. (21°23’10” N, 99°03’56” W); Cueva El Salitre, 450 m alt. (21°22’55” N, 98°57’53” W); Las Pozas, Xilitla (21°23’39” N, 98°59’44” W, 540 m alt.); Las Pozas, 560 m alt. (21°23’39” N, 98°59’44” W); arroyo at Las Pozas, 520 m alt. (21°24’08” N, 98°59’44” W) (Correa-Sandoval, et al, 1998). TAMAULIPAS: Aserrdero del Paraiso, 15 km NNW of Chamal (Solem, 1957); numerous localities in southern Tamaulipas (Correa-Sandoval & Castro, 2002).

Ceres salleana Gray, 1856

Ceres salleana Gray, 1856; Proc. Zool. Soc. London, 24: 100, 102 — Pfeiffer, 1876; Monogr. Pneumo. Viv., 4: 295 — Fischer & Crosse, 1900: 383; pl. 54, figs. 3-3d (shell) — Thompson, 1980; Malacologia, 24: 6, 17.

Proserpina (Ceres) salleana (Gray). Pfeiffer, 1856; Proc. Zool. Soc. London, 23: 322; pl. 35, figs. 21, 22 (shell) — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 332 — Von Martens, 1890: 45 — Von Martens, 1901; Biol. Cent. Amer.: 609.

TYPE LOCALITY — Cordova [Cordoba], Veracruz.

DISTRIBUTION RECORDS — VERACRUZ: Orizaba (Pilsbry, 1891); Huatusco, Barranca de Dos Puentes; Cerro de Palma, Sierra de Matlaquihuahuitl, nr. Toxpan (Von Martens, 1901).

Genus Linidiella Jousseaume, 1889

Linidiella Jousseaume, 1889; Mem. Zool. Soc. France, 2: 256 — H. B. Baker, 1923; Nautilus, 36: 84 — Thompson, 1980; Malacologia, 24: 19.

Chersodespoena Sykes, 1900; Proc. Malac. Soc. London, 4: 136.

TYPE SPECIES — Linidiella: Proserpina swifti Bland, 1863 (H. B. Baker, 1923). Chersodespoena: Despoena (Chersodespoena) cinnanomea Sykes, 1900 (monotypy).

DISTRIBUTION — Ecuador, Venezuela, eastern Mexico.

TAXONOMY — Four species are recognized. Two occur in Mexico.

Linidiella citrina Thompson, 1987

Linidiella citrina Thompson, 1987; Arch. für Mollusk., 117: 160-162; figs. 1, A-D (shell).

TYPE LOCALITY — 2 km NE of Comolapa, Veracruz; 450 m alt. (96º52’, W 18º42’ N). Holotype FLMNH 84367.

DISTRIBUTION — VERACRUZ: known only from the immediate viscinity of Comolapa.

Linidiella sulfureous Thompson, 1967

Linidiella sulfureous Thompson, 1967; Proc. Biol. Soc. Wash., 80: 61; figs. 1-3 (shell) — Thompson, 1987; Arch. für Mollusk., 117: 162; figs. 1, E-H (shell).

TYPE LOCALITY — 8.2 mi. S of Solusuchiapa, Chiapas; 1600 ft. alt. Holotype FLMNH 19025.

DISTRIBUTION RECORDS — CHIAPAS: known only from the type locality.

Genus Proserpinella Bland, 1865

Proserpinella Bland, 1865: 157 — Thompson, 1980; Malacologia, 24: 23-24.

TYPE SPECIES — Proserpinella berendti Bland, 1865 (monotypy).

DISTRIBUTION — Mexican states of Veracruz, Jalisco and Nayarit.

TAXONOMY — Three species are recognized.

Proserpinella berendti (Bland, 1865)

Proserpinella berendti Bland, 1865; Ann. Lyceum Nat. Hist. New York, 9: 157; fig. 2 (shell) — Strebel, 1873: 11; pl. 4, fig. 5 (shell) — Fischer & Crosse, 1901: 377; pl. 54, figs. 1-1d (shell) — Thompson, 1980; Malacologia, 24: 24.

Proserina (Proserpinella) berendti (Bland). Von Martens, 1890: 45 — Von Martens, 1901; Biol. Cent. Amer.: 609.

TYPE LOCALITY — Mirador, Veracruz.

DISTRIBUTION RECORDS — VERACRUZ: known only from the type locality.

Proserpinella edentula Naranjo-Garcia, 1994

Proserpinella edentula Naranjo-Garcia, 1994; Arch. für Mollusk., 123: 145-150; fig. 1 (shell), fig. 2 (radula), fig. 3 (female reproductive system).

TYPE LOCALITY — Jalisco, Municipio La Huerta, Estacion de Biologia Chemela, km 59, Hwy. 200 (ca. 19º29’ N, 104º58’ W). Holotype Universidad Nacional Autonomo de Mexico, Instituto de Biologia 260.

DISTRIBUTION RECORDS — JALISCO: known only from the type locality.

Proserpinella hannae Dall, 1926

Proserpinella hannae Dall, 1926; Proc. Calif. Acad. Sci., ser. 4, 15: 486-487; pl. 36, figs. 6-8 (shell) — Thompson, 1980; Malacologia, 24: 24.

TYPE LOCALITY — Maria Madre Island, Tres Marias Islands, Nayarit. Holotype CAS 2211.

DISTRIBUTION RECORDS — NAYARIT: known only from the type locality.

Family HELICINIDAE Férussac, 1822

DISTRIBUTION — The Neotropical Realm, the Pacific Islands, Australia, Indian Ocean islands and southeast Asia.

TAXONOMY — Numerous genera and subgenera. There is little consensus on the status and validity of many of these. The family HELICINIDAE is poorly studied, and new investigations will require many changes. A study by Richling (2004) is a major step in addressing many taxonomic problems in Central America and Mexico. Three subfamilies are recognized in the Neotropical region: Helicininae, Vianinae and Stoastominae. The subfamily Stoastominae is confined to the West Indies and coastal Venezuela.

SUBFAMILY HELICININAE Férussac, 1822

DISTRIBUTION — New World, ranging from Argentina north to the southeastern United States and throughout the West Indies.

TAXONOMY — Four genera of Helicininae occur in Mexico and Central America. Fifty-seven species and twelve subspecies are recognized in the area covered in this study. Careful studies of morphology, biogeography and ecology by H. B. Baker (1922, 1926, 1928) and Richling (2004) demonstrate that many forms that were previously considered subspecies or varieties are valid species. This summary relies heavily upon the work of Richling (2004).

Genus Ceochsma Thompson, 1968

Ceochasma Thompson, 1968, Proc. Biol. Soc. Wash., 81: 45.

Helicina (Ceochasma) (Thompson). Richling, 2004; Malacologia, 45: 426, 427.

TYPE SPECIES — By monotypy Ceochasma phrixina Thompson, 1968.

DISTRIBUTION — Colima, Mexico.

TAXONOMY — The systematic position of this genus remains uncertain (Richling, 2004; Malacologia, 45). A single species is recognized.

Ceochasma phrixina Thompson, 1968

Ceochasma phrixina Thompson, 1968; Proc. Biol. Soc. Wash., 81: 46-52; figs. 1-6 (shell), figs. 7-9 (operculum), figs. 10-11 (reproductive anatomy).

TYPE LOCALITY — A collapsed limestone ridge 0.3 mile east of Tamala, Colima; 500 ft alt. [Tamala is a small village ca. 2 km NE and ca. 6 km E of Tacolapa]. Holotype FLMNH 20138.

DISTRIBUTION — COLIMA: known only from the type locality.

Genus Helicina Lamarck, 1799

Helicina Lamarck, 1799: 76.

TYPE SPECIES — Helicina neritella Lamarck, 1799.

DISTRIBUTION — The West Indies, Mexico, Central America and South America.

TAXONOMY — Nine subgenera are recognized in this study. Helicina s. s., Oxyrhombus, Tristramia, Pseudoligygyra, Cinctella, Oligyra, “Gemma”, Analcadia and Sericea. The Superfamily Helicinoidea is a nearly morphostatic group of organisms in which the soft anatomy shows little differentiation between and within genera. In this case shell characters prove useful for grouping species, even though in some instances the distinctions between subgenera approach being arbitrary. H. B. Baker (1922a, 1926, 1928), Thompson (1968, 1980, 1982) and Richling (1903) provide information concerning the classification of the neotropical fauna. Richling greatly advances our knowledge of the Costa Rican fauna, and she proposes a clasification that recognizes fewer subgenera. The problem of integrating the rest of the Mexico and Central American species into the classification that she proposes requires recognition of additional subgenra. This study follows largely the subgeneric classification proposed by H. B. Baker (1928).

Subgenus Oligyra Say 1818

Olygyra Say, 1818.

Oligyra Say, 1819 (amended for Olygyra).

Orbiculata Wagner, 1905; Denksch. Kaiserli. Akad. …..

TYPE SPECIES — Oligyra orbiculata Say, 1818 (type by monotypy).

DISTRIBUTION — Southeastern United States, Mexico and Central America.

TAXONOMY — Three species and one subspecies occur within the area of this study.

Helicina (Oligyra) orbiculata orbiculata (Say, 1818)

Oligyra orbiculata Say, 1818; Jour. Acad. Nat. Sci. Phila., pt. 2: 283.

Oligyra (Oligyra) orbiculata orbiculata Say. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 44; pl. 3, fig. 2; pl. 4, fig. 11 (radula).

Helicina orbiculata Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 301; pl. 61, figs. 1-6 (shell) — Pilsbry, 1948; Land Moll. N. Amer., II: 1082-1084; figs. a-e (shell).

Helicina (Oligyra) orbiculata orbiculata Say. H. B. Baker, 1926; Proc. Acad. Nat. Sci. Phila., 78: 40; pl. 5, fig. 1 (reproductive anatomy).

Helicina hanleyana Pfeiffer, 1849; Proc. Zool. Soc. London (1848): 122 — Pfeiffer, 1852: 38; pl. 9, figs. 7-8 (shell).

TYPE LOCALITY — Ostershell Hammocks near the mouth of the St. John’s River, Florida. Holotype ANSP 10573.

DISTRIBUTION — In the United States the species is widely distributed in Florida, Georgia, Alabama, Tennessee, Mississippi, Louisiana, Arkansas and Oklahoma.

Numerous localities in southern TAMAULIPAS and eastern SAN LUÍS POTOSÍ (Correa-Sandoval, et al, 1998; Correa-Sandoval & Castro, 2002).

Helicina (Oligyra) orbiculata tropica Pfeiffer, 1852

Helicina tropica Pfeiffer, 1852: 37; pl. 4, figs. 9, 10 (shell).

Helicina orbiculata tropica Pfeiffer. Pilsbry, 1896: 534 — Pilsbry, 1948: 1048-1049; figs. f-h (shell).

Oligyra (Oligyra) orbiculata tropica (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 44.

Helicina (Oligyra) orbiculata tropica Pfeiffer. H. B. Baker, 1926; Proc. Acad. Nat. Sci. Phila., 78: 39-40; pl. 5, figs. 2-4.

TYPE LOCALITY — Not given.

DISTRIBUTION — COHUILA (Pilsbry, 1948). NUEVO LEóN: Santiago (Correa-Sandoval, 1993). TAMAULIPAS (Pilsbry, 1948).

Helicina (Oligyra) borealis Von Martens, 1890

Helicina borealis Von Martens, 1890; Biol. Cent. Amer.: 40; pl. 1, fig. 15 (shell) — Fischer & Crosse, 1893: 435 — Von Martens, 1901; Biol. Cent. Amer.: 606 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 300-301; pl. 60, figs. 1-3 (shell).

Oligyra Oligyra) borealis (Von Martens). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 44.

TYPE LOCALITY — Villa Lerdo, Durango, Mexco.

DISTRIBUTION — DURANGO: known only from the type locality.

Helicina (Oligyra) cordillerae Pfeiffer, 1857

Helicina cordillerae Pfeiffer, 1857; Proc. Zool. Soc. London (1856): 323 — Reeve, 1874; Conch. Icon., Helicina: pl. 16, fig. 149 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 32-33 — Fischer & Crosse, 1893: 412; pl. 57, figs. 1-1c, 2-2a (shell) — Von Martens, 1901; Biol. Cent. Amer.: 603 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 300; pl. 59, figs. 21-25 (shell).

Oligyra (Oliyra) codillerae (Pfeiffer). H. B. Baker. 1922; Proc. Acad. Nat. Sci. Phila., 74: 44.

TYPE LOCALITY — Volcán Orizaba, Rancheria de Jacale, Veracruz; 3500 m alt. (Fischer & Crosse, 1893).

DISTRIBUTION — VERACRUZ: known only from the type locality.

Subgenus Oxyrhombus Crosse & Fischer, 1893

Oxyrhombus Crosse & Fischer, 1893: 401.

Concentrica Wagner, 1905; Denksch. Kaiserli. Akad. ….: 282.

Punctisulcata Wagner, 1905; Denksch. Kaiserli. Akad. ….: 294.

Cinctella Wagner, 1910; in Martini Chemnitz, Syst. Conch. Cab., Helicinidae: 298.

TYPE SPECIES — Oxyrhombus: Helicina amoena (selected by H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 84). Concentrica: Helicina concentrica, Pfeiffer, 1849 (type by tautonomy). Punctisulcata: Helicina punctisulcata Von Martens, 1900 (type by tautonomy). Cinctella: Helicina cinctella Shuttleworth, 1852 (type by tautonomy).

DISTRIBUTION — Tamaulipas and Guerrero, Mexico south to Venezuela.

TAXONOMY — Eleven species are recognized within the area covered by this review. Additional species occur in northern South America.

Helicina (Oxyrhombus) amoena Pfeiffer, 1849

Helicina amoena Pfeiffer, 1945: 119 — Von Martens, 1890; Biol. Cent. Amer.: 28 — Fischer & Crosse, 1893: 401; pl. 55, figs. 3-3s, 4 — Fluck, 1906: 1 — Von Martens, 1901; Biol. Cent. Amer.: 602 — Fluck, 1906; Nautilus, 20: 1 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 295-296; pl. 59, figs. 10-12 (shell) — Bequaert, 1957; Bull. Mus. Comp. Zool., 115: 206 — Basch, 1959; Occ. Pap. Mus. Zool. Univ. Mich., (612): 7.

Helicina (Oxyrhombus) amoena Pfeiffer. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 48; pl. 3, fig. 8; pl. 4, fig. 15 (radula).

Helicina purpureo-flava Morelet, 1849; Test. Noviss., I: 19.

Helicina amoena var. minor Von Martens, 1890; Biol. Cent. Amer.: 28.

Helicina amoena var. depressa Von Martens, 1890; Biol. Cent. Amer.: 28.

TYPE LOCALITIES — Helicina amoena: Honduras. Helicina amoena var. ­minor: Nicaragua. Helicina amoena var. depressa: Bugaba, west of David, Panama. Helicina purpureo-flava: Petén, Guatemala.

DISTRIBUTION — PANAMA. NICARAGUA: nr. Wounta River (Kukallaya River, NW of Kukallaya (Fluck, 1906). GUATEMALA, Dept. Alta Verapaz: Coban (Von Martens, 1890). Dept. Baja Verapaz: San Juan; Sabo, 2800 ft. alt.; Chacoj; Panzos; Teleman (Von Martens, 1890). Dept. Petén: Tikal (Basch, 1959). CAMPECHE: (Von Martens, 1890). CHIAPAS: Laguna Ocatal, 950 m alt.; El Censo to Laguna Ocotal, 1000 m alt.; Ocosingo, 850 m alt.; El Real, 600 m alt.; Monte Libano, 600 m alt. (Bequaert, 1957). VERACRUZ (Wagner, 1910).

Helicina (Oxyrhombus) bocourti Crosse & Fischer, 1869

Helicina bocourti Crosse & Fischer, 1869; Jour. de Conchyl., 17: 251.

Helicina dysoni bocourti Crosse & Fischer. Fischer & Crosse, 1893: 437-438; pl. 56, fig. 10 (shell).

Helicina dysoni Pfeiffer. Simpson, 1897; Nautilus, 11: 13-14.

Oligyra (Analcadia) dysoni bocourti Crosse & Fischer. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 47.

Helicina (Tristramia) bocourti Crosse & Fischer. Rehder, 1966; Proc. Biol. Soc. Wash., 79: 276-277; figs. 8-10 (shell), figs. 18-20 (radula) — Richling, 2004; Malacologia, 45: 425.

Hwelicina dysoni var. jansoni Von Martens, 1890; Biol. Cent. Amer.: 40; pl. 1, fig. 18 (shell).

Alcadia (Analcadia) dysoni bocourti (Crosse & Fischer). Wagner, 1908: 90; pl. 15, figs. 16-19 (shell).

TYPE LOCALITY — Helicina bocourti: Utila Island, Honduras. Helicina dysoni var. jansoni: Bonacca Island [Isla Guanaja], Honduras.

DISTRIBUTION — HONDURAS, Isla Utila; Isla Roatán; Isla Guanaja. BELIZE: along the coast from Rocky Point to Puerto Honduras, near the Guatemala border. QUINTANA ROO: Bahia de Ascensión; Tulúm (Rehder, 1966).

Helicina (Oxyrhombus) cinctella cinctella Shuttleworth, 1852

Helicina cinctella Shuttleworth, 1852; in Bern Mittheil.: 304 — Von Martens, 1890; Biol. Cent. Amer.: 29 — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 332 — Fischer & Crosse, 1893: 403; pl. 55, figs. 6-6c, 7-7c (shell) — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 298-299; pl. 59, figs. 13-17 (shell) — Neubert & Gosteli: 11; pl. 8, fig. 2 (shell).

Helicina (Oxyrhombus) cinctella cinctella Shuttleworth. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 48 — H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 32; pl. 2, fig. 5; pl. 3, fig. 14 (reproductive anatomy).

TYPE LOCALITY — Cordova [Cordoba], Veracruz. Syntypes: NMBE 15275/3.

DISTRIBUTION — JALISCO: Tepic (Von Martens, 1890). VERACRUZ: Cordoba; Cerro de Plumas; Mirador; Orizaba (Von Martens, 1890); Sumidero (H. B. Baker, 1928).

Helicina (Oxyrhombus) cinctella bautistae Wagner, 1910

Helicina (Oxyrhombus) cinctella bautistae Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 209; pl. 59, figs. 18-20 (shell).

Helicina (Oxyrhombus) cinctella bautista Wagner. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 48.

TYPE LOCALITY — San Juan Bautista, Tabasco, Mexico. Holotype Holotype ZMB 103323.

DISTRIBUTION — TABASCO: known only from the type locality.

Helicina (Oxyrhombus) ghiesbreghti Pfeiffer, 1856

Helicina ghiesbreghti Pfeiffer, 1856: 381 — Von Martens, 1890; Biol. Cent. Amer.: 28 — Pilsbry, 1892: 339 — Fischer & Crosse, 1893: 399; pl. 55, figs. 5-5c (shell) — Von Martens, 1901; Biol. Cent. Amer.: 202 — Thompson, 1957; Nautilus, 70: 100.

Helicina (Oxyrhombus) ghiesbreghti Pfeiffer. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 47

Helicina ghiesbrighti Pfeiffer. Reeve, 1874; Conch. Icon., Helicina: pl. 27, fig. 242 (shell).

Helicina ghiesbreghti Pfeiffer. Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 296-297; pl. 59, figs. 3-5 (shell).

TYPE LOCALITY — Chiapas.

DISTRIBUTION — GUATEMALA: El Reposo, 8000 ft. alt.; San Francisco Miramar; Costa Cuca (Von Martens, 1890). CHIAPAS (Von Martens, 1890). TABASCO: mountains of Poana (Pilsbry, 1892); 0.5-1.0 mi. E of Teapa (Thompson, 1957).

Helicina (Oxyrhombus) heighwayana Dall, 1909

Helicina heighwayana Dall, 1909; Smiths. Misc. Coll., 52: 392 — Pilsbry, 1926; Proc. Acad. Nat. Sci. Phila., 78: 70; pl. 37, figs. 7-9 (shell).

TYPE LOCALITY — Sierra Darien, near the Rio Atrato, Panama. Holotype USNM 111074.

DISTRIBUTION — PANAMA: Rio Puerco (Pilsbry, 1926).

Helicina (Oxyrhombus) isthmica Pilsbry, 1926

Helicina isthmica Pilsbry, 1926; Acad. Nat. Sci. Phila., 78: 68; text-fig. 3B (shell).

TYPE LOCALITY — Rio Puerco, Panama. Holotype ANSP 140713.

DISTRIBUTION — PANAMA: known only from the type locality.

Helicina (Oxyrhombus) oxyrhyncha Crosse & Debeaux, 1863

Helicina oxyrhyncha Crosse & Debeaux, 1863: 266; pl. 9, fig. 4 (shell) — Pilsbry, 1926; Proc. Acad. Nat. Sci. Phila., 78: 69-70; text-figs. 3D, E, F (shell).

TYPE LOCALITY — not given.

DISTRIBUTION — PANAMA: Lowlands of Rio Tucuti, Panama (Pilsbry, 1926.

Helicina (Oxyrhombus) ptychophora Sykes 1902

Helicina ptychophora Sykes, 1902; Proc. Malac. Soc. London, 5: 20; text-fig. (shell) — Pilsbry, 1926; Proc. Acad. Nat. Sci. Phila., 78: 69-70.

TYPE LOCALITY — Guatemala.

DISTRIBUTION — GUATEMALA: exact localities are unknown.

Helicina (Oxyrhombus) sanguinea Pfeiffer, 1849; Proc. Zool. Soc. London (1848)

Helicina sanguinea Pfeiffer, 1849; Proc. Zool. Soc. London (1848): 124 — Sowerby, 1866; Thesaurus conch., 3: 292; pl. 275, figs. 364, 365 (shell) — Reeve, 1874; Conch. Icon., Helicina: pl. 20, fig. 178 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 40.

Oligyra (Analcadia) sanguinea (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 47.

TYPE LOCALITY — “Honduras”.

DISTRIBUIION — HONDURAS. Unknown.

Helicina (Oxyrhombus) sowerbyana Pfeiffer, 1849

Helicina sowerbyana Pfeiffer, 1849; Proc. Zool. Soc. London (1848): 124 — Von Martens, 1890; Biol. Cent. Amer.: 28-29 — Fischer & Crosse, 1893: 444 — Von Martens, 1901; Biol. Cent. Amer.: 602 — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 782; pl. 54, figs. 7-8 (shell) — Correa-Sandoval, Gutierrez & Reza, 1998; Acta Zool. Mex., (73): 13 — Correa-Sandoval & Castro, 2002; Acta Zool. Mex., (86): 235:

Helicina (Oxyrhombus) sowerbyana Pfeiffer. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 48.

TYPE LOCALITY — “Guatemala”.

DISTRIBUTION — NUEVO LEON: Santiago (Correa-Sandoval, 1993). SAN LUÍS POTOSÍ: Las Cascadas, Tamasopo (21º56’05” N, 99º25’00” W) (Correa-Sandoval, 1998); Las Cascadas, Tamasopo (21º56’05” N, 99º25’00” W) (Correa-Sandoval, et al, 1998). TAMAULIPAS: cañon 4 mi. W of Cd. Victoria (Pilsbry, 1903); Salto del Tigre (23º58’31” N, 99º22’24” W) (Correa-Sandoval & Castro, 2002).

Subgenus Succincta Wagner 1905

Succincta Wagner, 1905; Denksch. Kaiserli. Akad. …: 315.

Gemma Wagner, 1905; Denksch. Kaiserli. Akad. ….: (non Gemma Deshayes, 1853).

TYPE SPECIES — Succincta: Helicina succincta Von Martens, 1890. Gemma: Helicina gemma Preston, 1903.

DISTRIBUTION — Mexico and Central America.

TAXONOMY — Six species and six subspecies.

Helicina (Succincta) arenicola arenicola Morelet, 1849

Helicina arenicola Morelet, 1849; Test. Noviss., I: 21 — Von Martens, 1890; Biol. Cent. Amer.: 36 — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 332 — Fischer & Crosse, 1893: 424-425; pl. 56, figs. 8, 8a-c (shell) — Von Martens, 1901; Biol. Cent. Amer.: 605 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 316; pl. 63, figs. 11-13 (shell) — Richards, 1937; Proc. Amer. Philos. Soc., 77: 257 — Harry, 1950; Occ. Pap. Mus. Zool. Univ. Mich., (524): 29 — Rehder, 1966; Proc. Biol. Soc. Wash., 79: 276.

Oligyra (Succincta) arenicola (Morelet). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45 — Thompson, 1967; Bull. Fla. St. Mus., 11: 229.

TYPE LOCALITY — Sisal, Yucatan; in sandy places.

DISTRIBUTION — CAMPECHE: numerous localities (Thompson, 1967). QUINTANA ROO: Chancanab; Laguna Chichankanab, near Esmeralda; Tulum; San Miguel, Cozumel Island; San Gerbacio (Rehder, 1966); 7.1 mi. NNE of Xiatil; 2.3 mi. SSE of Xiatil (Thompson, 1967). YUCATAN: Silam; Ticul; Tabi; Uxmal; Tunkas; Santa Ana (Pilsbry, 1891); Chichen Itza; Progreso; 8 mi. S of Progreso; 8 mi. NW of Chichen Itza (Harry, 1950); 3.2 mi. S of Progreso; 1.0 mi. SSE of Puerto Telchac (Thompson, 1967).

Helicina (Succincta) arenicola raresulcata Pfeiffer, 1861

Helicina raresulcata Pfeiffer, 1861; Malak. Blätt., 8: 173 — Strebel, 1873: 119; pl. 1a, fig. 9; pl. 2, fig. 9 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 36 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 315; pl. 63, figs. 1-5 (shell).

Oligyra (Succincta) arenicola raresulcata (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

TYPE LOCALITY — Veracruz, [Veracruz], Mexico

DISTRIBUTION. — VERACRUZ: known only from the type locality.

Helicina (Succincta) flavida flavida Menke, 1828

Helicina flavida Menke, 1828: 79 — Strebel, 1873: 16; pl. 1a, figs. 10, 10a, 10b; pl. 2, fig. 10 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 38-39 — Fischer & Crosse, 1893: 433; pl. 56, figs. 6-63 (shell) — Von Martens, 1901; Biol. Cent. Amer.:606 — Hinkley, 1907; Nautilus, 21: 71 — Richling, 2004; Malacologia, 45: 386-387.

Oligyra flavida flaviada (Menke). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45 — Bequaert, 1957; Bull. Mus. Comp. Zool., 115: 206 — Thompson, 1967; Bull. Fla. St. Mus., 11: 229.

Helicina (Succincta) flavida flavida Menke. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 29-30; pl. 2, fig. 7 (reproductive anatomy).

TYPE LOCALITY — “Jamaica”.

DISTRIBUTION — COSTA RICA, Prov. Limón: Puerto Limón (Richling, 2004; Malacologia, 45). HONDURAS, Dept. Copán: Copán (Von Martens, 1901). GUATEMALA, Dept. Alta Verapaz: Coban (Von Martens, 1890). Dept. Baja Verapaz: Senahu (Von Martens, 1890). CAMPECHE: 10.2 mi. E of Escarcega; (Thompson, 1967). CHIAPAS: Laguna Ocotal, 950 m alt. (Bequaert, 1957; Bull. Mus. Comp. Zool., 115); Palenque (Thompson, 1967). PUEBLA: Necaxa (H. B. Baker, 1928). QUINTANA ROO: 4.0 mi. E

of Xpujil [Campeche] (Thompson, 1967). SAN LUÍS POTOSÍ: Carretara; Tamazunchale-El Taimán, 220 m alt. (21º14’23”N, 98º49’44” W); Carr. Jalpan-Xilitla, 6 km NW of Xilitla W, 830 m alt. (21º23’10” N, 99º03’56”); Las Pozas (arroyo), 520 m alt. (21º24’08” N, 98º59’44” W); Xilitla (21º22’55” N, 98º59’44” W); Las Cascadas, Tamasopo, (21º56’05” N, 99º05’00” W); Huichihuayan (21º28’32” N, 98º58’41” W); Los Ciruelos (21º18’02” N, 98º49’49” W); Barrio San Rafael, Tamazunchale (21º16’05” N, 98º46’03” W); Río Moctezuma, Tamazunchale (21º15’21” N, 98º48’56” W) (Correa, et al, 1998). TABASCO: Teapa; San Jan Bautista (Von Martens, 1890). TAMAULIPAS: Tampico (Hinkley, 1907). VERACRUZ: Papantla; Veracruz; Misantla; Mirador (Von Martens, 1890); San Rafael, Jicaltepec (Pilsbry, 1896); numerous localities in northern Veracruz (Correa-Sandoval, 2000).

Helicina (Succincta) flavida brevilabris Pfeiffer, 1857

Helicina brevilabris Pfeiffer, 1857; Proc. Zool. Soc. London (1856): 380 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 317-318; pl. 63, figs. 14-18 (shell).

Oligyra (Succincta) flavida brevilabris (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

TYPE LOCALITY — Chiapas.

DISTRIBUTION — CHIAPAS (Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae). TABASCO: Teapa; San Juan Bautista (Wagner, 1910). VERACRUZ: Cordoba; Mirador; Papantla; Misantla (Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae).

Helicina (Succincta) flavida incommoda Wager, 1905

Helicina brevilabris incommoda Wagner, 1905; Denksch. Kaiserli. Akad. …: 238; pl. 14, fig. 2 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 318; pl. 63, fig. 19 (shell).

TYPE LOCALITY — Guatemala.

DISTRIBUTION — GUATEMALA: no specific locality recorded.

Helicina (Succincta) flavida strebeli Pfeiffer, 1861

Helicina strebeli Pfeiffer, 1861; Malak. Blätt., 8: 173 — Strebel, 1873: 18; pl. 1, fig. 11 (shell); pl. 2, fig. 11 (shell).

Oligyra (Succincta) flavida strebeli (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 47; pl. 3, fig. 3; pl. 4, fig. 12 (radula).

Helicina (Succincta) flavida strebeli Pfeiffer. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 28-29.

TYPE LOCALITY — Mirador, Veracruz, Mexico.

DISTRIBUTION — PUEBLA: Necaxa, 2215-2625 ft. alt. (H. B. Baker, 1928). VERACRUZ: Mirador (18º59’ N, 96º14’ W).

Helicina (Succincta) oaxacana Pilsbry, 1920

Helicina oaxacana Pilsbry, 1920: 196; fig. 3 (shell).

Oligyra (Succincta) oaxacana (Pilsbry). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

TYPE LOCALITY — Puerto Angel, Oaxaca [Mexico].

DISTRIBUTION — OAXACA: known only from the type locality.

Helicina (Succincta) oweniana oweniana Pfeiffer, 1849

Helicina oweniana Pfeiffer, 1849: 123 — Pfeiffer, 1850: 40-41; pl. 7, figs. 35-36 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 38 — Fischer & Crosse, 1893: 429; pl. 56, figs. 4-4b, 4c (shell) — Von Martens, 1901; Biol. Cent. Amer.: 605-606 — Thompson, 1957: 100.

Alcadia (Leialcadia) oweniana (Pfeiffer). Wagner, 1908: 81; pl. 12, fig. 21-25 (shell).

Oligyra (Succincta) oweniana oweniana (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

Helicina (Succincta) oweniana oweniana Pfeiffer. Richling, 2004; Malacologia, 45: fig. 276 (shell).

TYPE LOCALITY — Chiapas, Mexico. Lectotype BMNH 20010751 (Richling, 2004).

DISTRIBUTION — GUATEMALA, Dept. Petén: Tikal National Park (Basch, 1959). MEXICO. TABASCO: Teapa; 0.5-1.0 mi. E of Teapa (Thompson, 1957). CHIAPAS: (Wagner, 1908).

Helicina (Succincta) oweniana anozona Von Martens, 1900

Helicina anozona Von Martens, 1875: 649 — Von Martens, 1876: 261; pl. 9, fig. 7 (shell).

Helicina oweniana anozona Von Martens. Fischer & Crosse, 1893: 429; pl. 56, figs. 4a, 5-5a (shell) — Richling, 2004; Malacologia, 45: 389; figs 278 (shell).

Alcadia (Leialcadia) oweniana anozona (Von Martens). Wagner, 1908: 82; pl. 12, figs. 26-28 (shell).

Oligyra oweniana var. anozona (Von Martens). Bequaert, 1957; Bull. Mus. Comp. Zool., 115: 206.

TYPE LOCALITY — Vicinity of Cobán, Alta Verapaz, Guatemala. Lectotype ZMB 25604a (Richling, 2004: 389).

DISTRIBUTION — GUATEMALA, Dept. Alta Verapaz: Cubilquitz. Dept. Baja Verapaz: Teleman (Von Martens, 1890). CHIAPAS: Monte Libano, 600 m alt.; El Real, 600 m alt. (Bequaert, 1957; Bull. Mus. Comp. Zool., 115: 206).

Helicina (Succincta) oweniana coccinostoma Morelet, 1849

Helicina coccinostoma Morelet, 1849; Test. Noviss., I: 19.

Helicina oweniana coccinostoma Morelet. Von Martens, 1890; Biol. Cent. Amer.: 38 — Fischer & Crosse, 1893: 429; pl. 56, figs. 4a, 5, 5a (shell) — Von Martens, 1901; Biol. Cent. Amer.: 605-606 — Richling, 2004; Malacologia, 45: 388-389; figs. 277 (shell).

Alcadia (Leialcadia) oweniana coccinostoma (Morelet). Wagner, 1908: 82; pl. 12, fig. 29 (shell).

Oligyra (Succincta) oweniana coccinostoma (Morelet). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45; pl. 5, fig. 24 (radula) — Bequaert, 1957; Bull. Mus. Comp. Zool., 115: 206.

TYPE LOCALITY — “Petenensis sylvas” [Dept. Petén], Guatemala. Lectotype: BMNH 1893.2.4.1605 (Richling, 2004: 388).

DISTRBUTIONS — GUATEMALA, Dept. Petén: Betalulen (Wagner, 1908). CHIAPAS: Laguna Ocatal, 950 m alt. (Bequaert, 1957; Bull. Mus. Comp. Zool., 115).

Helicina (Succincta) succincta Von Martens, 1890

Helicina succincta Von Martens, 1890; Biol. Cent. Amer.: 36; pl. 1, figs. 6, 9 (shell) — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 782 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 315-316; pl. 63, figs. 6-1 (shell).

Oligyra (Succincta) arenicola succincta (Von Martens). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

Helicina (Succincta) succincta Von Martens. H. B. Baker, 1928; Occ. Pap. Mus. Zol. Univ. Mich., (193): 30-31; pl. 4, fig. 26 (radula); pl. 2, figs. 3-4; pl. 3, fig. 13 (reproductive systems).

TYPE LOCALITY — Cordova [Cordoba], [Veracruz], Mexico.

DISTRIBUTION — PUEBLA: Necaxa (H. B. Baker, 1928). VERACRUZ: Texolo (Pilsbry, 1903); Tlacolula; Cuesta de Misantla (Von Martens, 1890).

Subgenus Gemma Wagner, 1905

Gemma Wagner, 1907: 81 — Richling, 2004; Malacologia, 45: 427 (non Gemma Deshayes, 1853).

TYPE SPECIES — Helicina gemma Preston, 1903.

DISTRIBUTION — Eastern Mexico and Central America..

TAXONOMY — We continue the use of the preoccupied subgeneric name Gemma, following Richling, because of the uncertain taxonomic status of closely related subgenera. It may be decided that Gemma is synonymous with Succincta, where H. B. Baker (1922) had placed the name. Twelve species and three subspecies are recognized in “Gemma”.

Helicina (Gemma) beatrix beatrix Angas, 1879

Helicina beatrix Angas, 1879; Proc. Zool. Soc. London: 484; pl. 40, fig. 13 (shell) — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 332 — Fischer & Crosse. 1893; Miss. Sci. Mex.: 435. Pilsbry, 1926b: 127 — Monge-Najera: 1997: 113.

Helicina flavida var. Von Martens, 1890; Biol. Cent. Amer.: 39.

Helicina flavida var. beatrix Angas. Von Martens, 1900; Biol. Cent. Amer.: 606.

Alcadia (Leialcadia) beatrix (Angas). Wagner, 1908; in Martini & Chemnitz, Helicineen: 83-84; pl. 14, figs. 19-22 (shell).

Oligyra (Succincta) beatrix beatrix (Angas). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

Helicina (Oligyra) beatrix Angas. Pilsbry, 1926a: 59, 69, 71; fig. 3A (shell) — Pilsbry, 1926b: 127.

Helicina (“Gemma”) beatrix bearix Angas. Richling, 2004; Malacologia, 45: 283-297; figs. 98, 100-103 (shell); fig. 104 (operculum); fig. 105a-c (radula); figs. 106-107 (female reproductive system); fig. 120 (map).

TYPE LOCALITY — Costa Rica, only on hills up to 2500 ft. alt. Lectotype BMNH 1879.7.22.79 (Richling, 2004).

DISTRIBUTION — COSTA RICA; Carribean mountain slopes of the Cordierra Central and the Cordierra de Talamanca in the Provs. Cartago, Limón, and San José (Richling, 2004).

Helicina (Gemma) beatrix confusa (Wagner, 1908)

Alcadia (Liealcadia) beatrix confusa Wagner, 1908: 84; pl. 14, fig. 25 (shell).

Oligyra (Succincta) beatrix confusa (Wagner). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

Helicina (“Gemma”) beatrix confusa (Wagner). Richling, 2004; Malacologia, 45: 297-303; figs. 123-126 (shell); fig. 127 (operculum); figs. 128-129 (female reproductive system); fig. 130 (map).

TYPE LOCALITY — Alto Tararia (ca. 09º14’30” N, 83º00’30” W), or downstream, Limón Prov., Costa Rica; 2500 m alt. Lectotype MIZ 8409 (Richling, 2004).

DISTRIBUTION — COSTA RICA, the SE area of Prov. Limón below 400 m alt. (Richling, 2004: fig. 130).

Helicina (Gemma) beatrix nicaraguae (Wagner 1908)

Alcadia (Leiacadia) nicaraguae Wagner, 1908: 84; pl. 14, figs. 23-24 (shell).

Helicina (“Gemma”) beatrix nicaraguae (Wagner). Richling, 2004; Malacologia, 45: 284; figs. 99, 121 (shell).

TYPE LOCALITY — Nicaragua. Lectotype MIZ 8408 (Richling, 2004).

DISTRIBUTION — NICARAGUA: exact locality unknown (Wagner, 1908). PANAMA, Isla Colón: Las Gratas, 5 km NNW of Bocas del Toro (09º24’23” N, 82º16’15” W); interior of Colón Island (Richling, 2004).

Helicina (Gemma) beatrix riopejensis Richling, 2004

Helicina (“Gemma”) beatrix riopejensis Richling, 2004; Malacologia, 45: 303-308; figs. 131-135 (shell); fig. 136 (operculum); fig. 137-138 (female reproductive system); fig. 139 (map).

TYPE LOCALITY — SW of Liverpool, ca. 24 km W of Puerto Limon along the Rio Peje (09º55’46” N, 83º13’15” W), Limon Prov., Costa Rica. Holotype UCR-INBio 3542625.

DISTRIBUTION — COSTA RICA, Limon Prov.: known only from the immediate vicinity of the type locality.

Helicina (Gemma) chiquitica (Richling, 2001)

Oligyra chiquitica Richling, 2001; Schriften zur Malak.; Schriften zur Malak.: 1-2; figs. 1 (operculum), 2 (shell).

Helicina (“Gemma”) chiquitica (Richling). Richling, 2004; Malacologia, 45; 357-364; figs. 228-231 (shell), fig. 232 (operculum), fig. 233 (radula); fig. 234 (female reproductive system), fig. 241 (distribution).

TYPE LOCALITY — Approx. 9 km W of Matina, a little stream on the Rio Barbilla from the crossing of the road Siquierres to Limón, along a tributary of the Rio Barbilla, Limón Province, Costa Rica, (10º03’29” N, 83º22’24” W). Holotype: UCR-INBio 3404977.

DISTRIBUTION — COSTA RICA, Cartago Prov.: Parque Nacional Barbilla, 500 m alt. (09º58’26” N, 83º27’28” W); Zona Protectora Rio Pacuare, Sector de La Estacion de Barbilla, 500 m alt. (09º50’50” N, 83º27’08” W). Heredia Prov.: S of Puerto Viejo de Sarapiqui, Zona Protectora La Selva, 60 m alt. (10º25’35” N, 84º00’18” W). Limón Prov.: S of Siquierres, along footpath stream up to Rio Pacuarito, 110 m alt. (10º05’38” N, 83º28’11” W) (Richling, 2004).

Helicina (Gemma) diaphana Pfeiffer, 1852

Helicina diaphana Pfeiffer, 1852: 98.

Helicina (“Gemma”) diaphana Pfeiffer. Richling, 2004; Malacologia, 45: 336; fig. 188 (shell).

Oligyra (Analcoadia) dysoni diaphana (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 47.

TYPE LOCALITY — Honduras. Possible syntypes BMNH 196282 (Richling, 2004).

DISTRIBUTION — HONDURAS: no other locality information given.

Helicina (Gemma) escondida Richling, 2004

Helicina (“Gemma”) escondida Richling, 2004; Malacologia, 45; 341-357; figs. 210-215 (shell), fig. 216 (operculum), fig. 217 (radula), fig. 218 (female reproductive system), fig. 227 (distribution).

TYPE LOCALITY — Costa Rica, Limón Prov., approximately 9 km W of Matina, a little upstream on the Rio Barbilla from the crossing of the road from Siquirres to Limón, along a tributary of the Rio Barbilla, 60 m alt. (10º02’29” N, 83º22’24” W). Holotype UCR-INBio 354263.

DISTRIBUTION — COSTA RICA: known only from Cartago Prov. and Limón Prov., from below 800 m alt. Cartago Prov.: Turrialba, International American Agricultural Institute, 600 m alt. (ca. 09º54’30” N, 83º41’ W). Limón Prov.: S of Puerto Viejo Sarapiqui, La Selva, 60 m alt. (10º25’53” N, 84º00’18 W); Cerro Mirado, 430 m alt. (09º36’37” N, 82º57’43” W); Sector Hitoy Cerere, Sendero Bobcara, 200 m alt. (09º40’31” N, 83º00’31” W); NE of Esatcion de Hitoy Cerere Sendero La Finca, 110 m alt. (09º40’36” N, 83º01’26” W); Sendero Bobocara, 798 m alt. (09º40’02” N, 83º04’09” W); Los Diamantes Farm, 20 km SE of Guapiles (ca. 10º11’ N, 83º37’ W); road along S bank of Rio Banano, opposite La Bomba (09º54’49” N, 83º03’56” W); Talamanca, Rio Estrella (09º43’ N, 83º00’ W). (All records from Richling, 2004.)

Helicina (Gemma) fragilis fragilis Morelet, 1851

Helicina fragilis Morelet, 1851; Test. Noviss., II: 17 — Von Martens, 1890; Biol. Cent. Amer.: 35 — Fischer & Crosse, 1893: 420; pl. 57, figs. 7-7b, 9-9b (shell) — Von Martens, 1901; Biol. Cent. Amer.: 605 — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 782.

Helicina (“Gemma”) fragilis Morelet. Richling, 2004; Malacologia, 45: 334; figs. 185-186 (shell).

Alcadia (Leialcadia) fragilis (Morelet). Wagner, 1908: pl. 14, figs. 9-12 (shell).

Oligyra (Succincta) fragilis fragilis (Morelet). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

TYPE LOCALITY — Sylvas Petenenses, Dept. Petén, Guatemala. Lectotype BMNH 1893.2.4.809 (Richling, 2004).

DISTRIBUTIONGUATEMALA, Dept. Alta Verapaz: Coban (Wagner, 1908). Dept. Baja Verapaz: Teleman, in the valley of the Rio Polochic; Purula, 4000 ft. alt. (Von Martens, 1890). GUERRERO: Omilteme, 8000 ft. alt. (Von Martens, 1890). VERACRUZ; Orizaba (Von Martens, 1901).

Helicina (Gemma) fragilis elata Shuttleworth, 1852

Helicina elata Shuttleworth, 1852; in Bern Mittheil.: 304.

Helicina (“Gemma”) elata Shuttleworth. Richling, 2004; Malacologia, 45: 336; fig. 187 (shell).

Helicina fragilis Morelet (in part). Von Martens, 1890; Biol. Cent. Amer.: 35.

Oligyra (Succincta) fragilis elata (Shuttleworth). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

Helicina (Succincta) fragilis elata Shuttleworth. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 27-28; pl. II, fig. 8 (female reproductive anatomy).

TYPE LOCALITY — Cordova [Cordoba], Veracruz, Mexico.

DISTRIBUTION — VERACRUZ: Atoyac to Sumidero (H. B. Baker, 1928).

Helicina (Gemma) gemma Preston, 1903

Helicina gemma Preston, 1903: 4; text-fig. (shell).

Alcadia (Leialcadia) gemma (Preston). Wagner: 83; pl. 14, figs. 17-18 (shell).

Oligyra (Succincta) gemma (Preston). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

Helicina (“Gemma”) gemma Preston. Richling, 2004; Malacologia, 45: 318-334; figs. 159-162 (shell); 167-168 (radula); figs. 169-171 (female reproductive system); fig. 182 (distribution).

TYPE LOCALITY — San Carlos [Ciudad Quesada (10º20’ N, 84º26’ W), Costa Rica. Lectotype BMNH 1903.5.4.2 (Richling, 2004).

DISTRIBUTION — COSTA RICA; generally distributed throughout the Caribbean slope of the northeastern sector of the country below 1200 m alt. NICARAGUA. Dept. Zelaya Norte: Cerro Salaya, Bosawas (Richling, 2004).

Helicina (Gemma) merdigera Pfeiffer, 1855.

Helicina merdigera Pfeiffer, 1855: 102.

Helicina (“Gemma”) merdigera Pfeiffer. Richling, 2004; Malacologia, 45: 334; figs. 183-184 (shell).

Helicina fragilis Morelet (in part). Von Martens, 1890; Biol. Cent. Amer.: 35.

Oligyra (Succincta) fragilis merdigera (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 45.

TYPE LOCALITY — Veracruz [City], [Veracruz], Mexico. Lectotype BMNH 20010752.1 (Richling, 2004).

DISTRIBUTION — VERACRUZ: known only from the type locality.

Helicina (Gemma) mohriana Pfeiffer, 1861.

Helicina mohriana Pfeiffer, 1861; Malak. Blätt., 8: 172-173.

Helicina (“Gemma”) mohriana Pfeiffer. Richling, 2004; Malacologia, 45: 334.

Alcadia (Leialcadia) mohriana (Pfeiffer). Wagner, 1908: 85; pl. 14, figs. 13-16 (shell).

TYPE LOCALITY — Orizaba, Mexico. Type specimens lost (Richling, 2004).

DISTRIBUTION — VERACRUZ: Orizaba; Cordoba (Wagner, 1908).

Helicina (Gemma) monteverdensis Richling, 2004

Helicina (“Gemma”) monteverdensis Richling, 2004; Malacologia, 45: 334-348; figs. 189-194 (shell); fig. 195 (operculum); fig. 196 (radula); figs. 197-199 (female reproductive system); fig. 209 (distribution).

TYPE LOCALITY — Cloud forest, Sendero Bosque Nuboso Monteverde, Reserva Biologica Bosque Nebosos, Cordillera Tilarán near Monterverde, Puntarenas Prov., Costa Rica.

DISTRIBUTION — COSTA RICA: numerous localities in Alajuela, Guanecaste, and Puntarenas Provinces in the immediate vicinity of the type locality. Prov. Guanacaste: 6 mi. NNE of Tilarán (ca. 10º33 N, 84º59 W); Prov. San Jose: Alta La Palma (ca. 10º03’ N, 84º00 W) (Richling, 2004).

Helicina (Gemma) talamancensis (Richling, 2001)

Oligyra talamancensis Richling, 2001; Schriften zur Malak.: 3-5; fig. 3 (shell), 4 (operculum).

Helicina (“Gemma”) talamancensis (Richling). Richling, 2004; Malacologia, 45: 308-318; figs. 140, 142-144 (shell); fig. 145 (operucum); figs. 146a-c (radula); figs. 147-148 (female reproductive systems); fig. 158 (map).

TYPE LOCALITY — Primary forest bordered by secondary growth, Fila Costeña, north of Bajo Bonta, north of Rio Claro, Puntarenas Prov., Costa Rica, 980 m alt., 08º44’41” N, 83º02’03” W. Holotype: UCR-INBio 3404978.

DISTRIBUTION — COSTA RICA: Puntarenas Prov. and San José Prov. Know from numerous localities in the south-central region of the Cordillera Talamanca (Richling, 2004).

Helicina (Gemma) terryae Rehder, 1940

Helicina terryae Rehder, 1940: 350; fig. 16.

Helicina (“Gemma”) terryae Rehder. Richling, 2004; Malacologia, 45: 308, 316; fig. 141 (shell).

TYPE LOCALITY — Chiriquí Prov., Panama. Holotype USNM 536026 (Richling, 2004).

DISTRIBUTION — PANAMA: known only from the type locality.

Subgenus Tristramia Crosse, 1863

Tristramia Crosse & Fischer, 1863.

Caloplisma Crosse & Fischer in Fischer & Crosse, 1893: 405.

Retorquata Wagner, 1905; Denksch. Kaiserli. Akad……

Turbinata Wagner, 1905; Denksch. Kaiserli. Akad…..: 306.

Rostrata Wagner, 1905; Denksch. Kaiserli. Akad…..

TYPE SPECIES — Tristramia: type by monotypy Helicina salvini Tristram, 1861 (= Helicina rostrata Morelet, 1849. Caloplisma: type by monotypy Helicina rostrata Morelet, 1849. Retorquata: Helicina zephyrina Duclos, 1833 (first species). Turbinata: type by tautonomy Helicina turbinata Pfeiffer, 1846. Rostrata: type by tautonomy Helicina rostrata Morelet, 1849.

DISTRIBUTION — Mexico and south to Colombia.

TAXONOMY — Numerous species. Eighteen species and seven subspecies are recognized in Mexico and Central America.

Helicina (Tristramia) chrysocheila chrysocheila Binney, 1851

Helicina chrysocheila Binney, 1851: 354; pl. 74, fig. 4 )shell) — Von Martens, 1890; Biol. Cent. Amer.: 33-34 — Pilsbry, 1948: 1081-1082; figs. 578, d (shell) — Correa-Sandoval, 1993; Rev. Biol. Trop., 41: 685 — Correa-Sandoval, Gutierez & Reza, 1998; Acta Zool. Mex., (73): 13 — Correa-Sandoval, 2000; Acta Zool. Mex., (79): 8 — Correa-Sandoval & Castro, 2002; Acta Zool. Mex., (86): 235.

Helicina (Tristramia) chrysocheila chrysocheila Binney. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

TYPE LOCALITY — No locality given.

DISTRIBUTION — NUEVO LEON: numerous localities in southern Nuevo Leon (Correa-Sandoval, 1993). SAN LUÍS POTOSÍ: numerous localities in southeastern part of state (Correa-Sandoval, et al, 1998); 0.1 km W of Ejido Buenavista km 18, Carr. Mante-Cd. Valles, 320 m alt. (22º30’43” N, 99º01’50” W); Carr. Cd. Valles-Agua Buena km 37, 460 m alt. (21º53’24” N, 99º19’44” W); 2 km NW Poza de la Media Luna, 1070 m alt. (21º53’39” N, 100º03’56” W); Cascadas El Salto, 500 m alt. (22º34’38” N, 99º22’53” W); Carr. Cd. del Maíz-El Naranjo, km 35 (22º30’00” N, 99º22’06” W); Carr. Cd. del Maíz — El Naranjo (22º30’58” N, 99º20’15” W) (Correa-Sandoval, et al, 1998). TAMAULIPAS: numerous localities (Correa-Sandoval & Castro, 2002). VERACRUZ: numerous localities in the northern part of state (Correa-Sandoval, 2000).

Helicina (Tristramia) chrysocheila schuttleworthi Von Martens, 1890

Helicina chrysocheila Shuttleworth, 1852; in Bern Mittheil.: 303 — Neubert & Gosteli, 2005; Contr. Nat. Hist., 5: 9; pl. 8, fig. 1 (Shell).

Helicina chrysocheila var. shuttleworthi Von Martens, 1890; Biol. Cent. Amer.: 33; pl. 1, fig. 13 (shell).

Helicina (Tristramia) chrysocheila schuttleworthi Von Martens. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

TYPE LOCALITY — Cordova, Veracruz. Holotype NMBE 15267.

DISTRIBUTION — VERACRUZ: known only from the type locality.

TAXONOMY — There seems to be little basis for recognizing shuttleworthi as distinct from H. chrysocheila.

Helicina (Tristramia) delicatula Shuttleworth, 1852

Helicina delicatula Shuttleworth, 1852; in Bern Mittheil.: 303 — Von Martens, 1890; Biol. Cent. Amer.: 37 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 310-311; pl. 62, figs. 4-6 (shell) — Neubert & Gosteli, 2005; Contr. Nat. Hist., 5: 11; pl. 8, fig. 3 (shell).

Helicina (Tenuis) delicatula delicatula Shuttleworth. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 50.

Helicina (Oligyra) delicatula Shuttleworth. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 25-27; pl. II, fig. 2, pl. 3, fig. 12 (reproductive anatomy).

Helicina heloisiae Pfeiffer, 1856: 322 — Sowerby, 1866; Thes. Conch., 3: 288; pl. 272, figs. 283-284 (shell) — Wagner, 1905; Denksch. Kaiserli. Akad…..: 232; pl. 13, fig. 10 (shell).

TYPE LOCALITY — Cordova [Cordoba], Veracruz. Holotype: NMBE 19074.

DISTRIBUTION — VERACRUZ: Cordoba; Atoyac (Von Martens, 1890).

Helicina (Tristramia) durangoana durangoana Mousson, 1883

Helicina durangoana Mousson, 1883: 218; pl. 9, fig. 8 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 37 — Fischer & Crosse, 1893: 426; pl. 56, figs. 7-7c (shell) — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 305; pl. 60, figs. 4-6 (shell).

Helicina (Tenuis) durangoana durangoana Mousson. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 50.

TYPE LOCALITY — Sierra Madre, Durango, Mexico.

DISTRIBUTION — DURANGO: Ventanas (Von Martens, 1890).

Helicina (Tristramia) durangoana sagulensis Wagner, 1910

Helicina durangoana sagulensis Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 305; pl. 60, fig. 7 (shell).

Helicina (Tenuis) durangoana sagulensis Wagner. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 50.

TYPE LOCALITY — Sagula, Jalisco, Mexico.

DISTRIBUTION — JALISCO: known only from the type locality.

Helicina (Tristramia) echandiensis Richling, 2004

Helicina echandiensis Richling, 2004; Malacologia, 45: 271-277; figs. 77-81 (shell); fig. 82 (operculum); fig. 83 (radula); fig. 84 (female reproductive anatomy).

TYPE LOCALITY — Parque Nacional de Amistad, Sector Las Alturas, southern Cordillera de Talamanca, S of Cerro Echandi, campamento Echandi, 2840 m alt. (09º01’33” N, 82º49’12” W), Puntarenas Prov., Costa Rica. Holotype UCR-INBio 3542520.

DISTRIBUTION — COSTA RICA: known only from the type locality.

Helicina (Tristramia) elatior Von Martens, 1890

Helicina turbinata Pfeiffer. Strebel, 1874: 13; pl. 1a, figs. 6b, c, f (shell).

Helicina zephyrina var. elatior Von Martens, 1890; Biol. Cent. Amer.: 31.

Helicina elatior Von Martens. Dall, 1905; Smiths. Misc. Coll., 48: 48: 192.

TYPE LOCALITY — Not stated.

DISTRIBUTION — SAN LUIS POTOSÍ: Alvarez Mountains; San Dieguito (Dall, 1905). VERACRUZ: Papantla; Misantla; Mirador; Rio Misanla; Cordoba (Von Martens, 1890).

Helicina (Tristramia) fasciata providentiae Pilsbry, 1930

Helicina (Tristramia) fasciata providentiae Pilsbry, 1930: 248-249, text-fig. 9 (shell).

TYPE LOCALITY — Old Providence Island, ridge north of High Peak and valley running westward. Holotype ANSP 150717.

DISTRIBUTION — COLOMBIA: known only from the type locality.

Helicina (Tristramia) funcki Pfeiffer, 1849

Helicina funcki Pfeiffer, 1849; Proceedings of the Zoological Society of London, 16 (1848): 121 — Pfeiffer, 1850: 33; pl. 9, figs. 1, 2 (shell) — Reeve, 1874; Conch. Icon., Helicina: pl. 17, fig. 152 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 33 — Ancey, 1897: 87 — Von Martens, 1900: 603-604 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 306-307; pl. 61; figs. 11-15 (shell) — Pilsbry, 1920a: 3 — Pilsbry, 1926; Proc. Acad. Nat. Sci. Phila., 78: 59, 69, 71; fig. 3c (shell) — Pilsbry, 1926; Proc. Acad. nat. Sci. Phila., 78: 127 — Peréz, 1994: 746 — Monge-Nájero, 1997: 113.

Helicina (Retorquata) funcki Pfeiffer. Wagner, 1905; Denksch. Kaiserli. Akad. ….: 232-233.

Helicina (Retorquata) funcki costaricensis Wagner, 1905; Denksch. Kaiserli. Akad…… 233; pl. 13; figs. 12a-12c (shell) — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 307; pl. 61, fig. 16 (radula) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

Helicina deppeana parvidens Pfeiffer. Pilsbry, 1920a: 3.

Helicina (Tristramia) funcki parvidens Pilsbry. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

Helicina (Tristramia) funcki funcki Pfeiffer. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51 — H. B. Baker, 1926; Proc. Acad. Nat. Sci. Phila., 76: 42; pl. 5, figs. 8; pl. 6, fig. 9 (female and male reproductive systems).

Helicina (Tristramia) funcki Pfeiffer. Richling, 2004; Malacologia, 45: 215-245; figs. 10-15, 26 (shell), fig. 16 (operculum), fig. 17 (radula), figs. 18-19 (female reproductive system); fig. 39 (Costa Rica, distribution).

TYPE LOCALITIES — Helicina funcki: San Yago [Santiago], Veraguas Prov., Panama; lectotype: BMNH 20010497.1 (Richling, 2004). Helicina funcki costariceneis: Sta. Clara [ca. 7 km NW of Upala, 10º56’ N, 85º05’ W]. Alajuela Prov., Costa Rica; 250 m alt.; lectotype MIZ 8989a (Richling, 2004). Helicina deppeana parvidens: Juan Viñas, Cartago Prov., Costa Rica; 3300 ft. alt. [ca. 09º 54’ N, 83º44’30” W]; holotype ANSP 105286.

DISTRIBUTION — COSTA RICA: numerous localities up to about 1600 m in the Provs. Alajuela, Cartago, Guanacaste, Heredia, Limón, Puntarenas and San José (Richling, 2004). NICARAGUA, Dept. Rio San Juan: Greytown (Ancey, 1897). PANAMA: numerous localities in Depts. Bocas del Toro, Colón and Canal Zone (Richling, 2004). COLOMBIA: Santiago (Von Martens, 1890).

Helicina (Tristemia) hondurana Richards, 1938

Helicina hondurana Richards, 1938; Proc. Amer. Philos. Soc., 79: 174-175; pl. 3, figs. 8, 9 (shell).

TYPE LOCALITY — West End, Roatán Island, Honduras. Holotype ANSP 17019.

DISTRIBUTION RECORDS — HONDURAS: known only from Roatán Island.

Helicina (Trisramia) notata Pfeiffer, 1856

Helicina delicatula notata Pfeiffer, 1856: 323 — Von Martens, 1890; Biol. Cent. Amer.: 38 — Fischer & Crosse, 1893: 431; pl. 56; figs. 10-10b, 11-11a (shell) — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 319; pl. 62, figs. 23-28 (shell).

Helicina (Tenuis) tenuis notata Pfeiffer. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 50.

Helicina (Tristramia) notata Pfeiffer. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 27.

TYPE LOCALITY — Cordova [Cordoba], Veracruz, Mexico.

DISTRIBUTION — VERACRUZ: Atoyac (Von Martens, 1890).

Helicina (Tristramia) pitalensis Wagner, 1910

Helicina pitalensis Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 308; pl. 61, figs. 17-19 (shell).

Helicina (Tristramia) pitalensis Wagner. Richling, 2004; Malacologia, 45: 246-254; figs. 40-43, 52 (shell), fig. 44 (operculum), fig. 45 (radula), fig. 46 (female reproductive system), fig. 53 (distribution).

Helicina funcki Pfeiffer. Von Martens, 1900; Biol. Cent. Amer.: 33 (in part).

Helicina (Tristramia) funcki pitalensis Wagner. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51

Helicina amoena Pfeiffer. Monge Nájero, 1997: 113.

TYPE LOCALITY — El Pital (nr. Londres, ca. [09º27’ N, 84º05’ W), Puntarenas Prov., Costa Rica. Holotype ZMB 103240.

DISTRIBUTION — COSTA RICA, numerous localities in Alajuela Prov. and Puntarena Prov. (Richling, 2004).

Helicina (Tristramia) punctisulcata punctisulcata Von Martens, 1890

Helicina punctisulcata Von Martens, 1890; 36-37; pl. 1, fig. 10 (shell) — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 294-295; pl. 59, fig. 6-8 (shell) — Richling, 2004; Malacologia, 45: 277; pl. 87 (shell).

Helicina (Oxyrhomba) punctisulcata punctisulcata Von Martens. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 48.

TYPE LOCALITY — Omilteme, Sierra Madre del Sur, Guerrero, Mexico. Lectotype ZMB 103326a (Richling, 2004).

DISTRIBUTION — GUERRERO: known only from the type locality.

Helicina (Tristramia) punctisulcata cuericensis Richling, 2004

Helicina punctisulcata cuericensis Richling, 2004; Malacologia, 45: 277-283; figs. 89-93 (shell); fig. 94 (operculum); figs. 95a-c (radula); fig. 96 (female reproductive system).

TYPE LOCALITY — Estacion Cuerici, 4.5 km E of De Villa Mills, Sendero El Mirador, Cordillera de Talamanca, San Jose Prov., Costa Rica (09º33’28” N, 83º40’13” W). Holotype UCR-INBio 3542622.

DISTRIBUTION — COSTA RICA: known only from the immediate vicinity of the type locality.

Helicina (Tristramia) punctisulcata zunilensis Wagner, 1910

Helicina punctisulcata zunilensis Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 295; pl. 59, fig. 6 (shell) — Richling, 2004; Malacologia, 45: 278; fig. 88 (shell).

Helicina (Oxyrhomba) punctisulcata zunilensis Wagner. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 48.

TYPE LOCALITY — Volcán Zuníl at border of Dept. Quetzaltenango and Dept. Sololá, Guatemala. Holotype ZMB 103324 (Richling, 2004).

DISTRIBUTION — GUATEMALA: known only from the type locality.

Helicina (Tristramia) rostrata rostrata Morelet, 1849

Helicina rosrata Morelet, 1849; Test. Noviss., I: 17 — Tate, 1870; Amer. Jour. Conch., 5: 159 — Sowerby, 1866; Thes. Conch., 3: 288; pl. 273, figs. 279-280 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 30 — Fischer & Crosse, 1893: 465; pl. 55, figs. 8-8c (shell) — Von Martens, 1901; Biol. Cent. Amer.: 603 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 313; pl. 62, figs. 15-18 (shell) — Richards, 1939; Proc. Amer. Philos. Soc., 81: 34-35; fig. 4 (shell) — Peréz & Lopéz, 2002: 45-46.

Helicina (Tristramia) rostrata rostrata Morelet. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

Helicina salvini Tristram, 1861; Proc. Zool. Soc. London: 233; pl. 26, figs. 9-10 (shell).

Helicina rostrata var. simplex Fischer & Crosse, 1893: 465; pl. 55, figs. 9-9c (shell).

TYPE LOCALITIES — Helicina rostrata: San Agustin Lanquin, Alta Vera Paz, Guatemala. Helicina salvini: Guatemala. Helicina rostrata var. simplex: not stated.

DISTRIBUTION — GUATEMALA, Dept. Alta Verapaz: Coban NICARAGUA, Dept. Chontales: Acoyapa (Von Martens, 1890). Dept. Managua: San Diego (Tate, 1870); Managua (Von Martens, 1901). Reg. Autonono Atlantico Sur: Corn Island (Richards, 1939). Depts. Chontales, Boaco and León (Perés & Lopéz, 2002).

Helicina (Tristramia) rostrata denticulata Pfeiffer, 1955

Helicina denticulata Pfeiffer, 1855; Proc. Zool. Soc. London: 103 — Tate, 1970; Amer. Jour. Conch., 5: 159 — Sowerby, 1866; Thes. Conch., 3: 288; pl. 273, fig. 281 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 30 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 314; pl. 62, figs. 20-22 (shell).

Helicina (Tristramia) rostrata denticulata Pfeiffer. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

TYPE LOCALITY — San Pedro [San Pedro Sula], Honduras.

DISTRIBUTION — HONDURAS: known only from the type locality. NICARAGUA: forests of Chontales (Von Martens, 1890).

Helicina (Tristramia) rostrata matagalpensis Wagner, 1910

Helicina rostrata matagalpensis Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 313-314; pl. 62, fig. 19 (shell).

Helicina (Tristramia) rostrata matagalpensis Wagner. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

TYPE LOCALITY — Matagalpa, Nicaragua.

DISTRIBUTION — NICARAGUA: known only from the type locality.

Helicina (Tristramia) senachuensis Wagner, 1905

Helicina vernalis senachuensis Wagner, 1905; Denksch. Kaiserli. Akad. ….: 234; pl. 13, fig. 15 (shell).

Helicina senachuensis Wagner. Wagner 1910a: 304; pl. 61, figs. 7-10 (shell).

Helicina (Tenuis) senachuensis Wagner. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 50.

TYPE LOCALITY — “Senachu”, Guatemala,

DISTRIBUTION — GUATEMALA: known only from the type locality. I have been unable to locate Senachu. There is a locality in Dept. Alta Verapaz named Senahu (15.4 N, 89.8 W).

Helicina (Tristramia) sinuosa Pfeiffer, 1850

Helicina sinuosa Pfeiffer, 1850; Zeitschr. Malak.: 191 — Von Martens, 1890; Biol. Cent. Amer.: 32 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 297-298; pl. 59, figs. 1-2 (shell).

TYPE LOCALITY — Mexico.

DISTRIBUTION — Unknown.

REMARKS — Status uncertain; this may be synonymous with Helicina zephyrina Duclos, 1833.

Helicina (Tristramia) tenuis Pfeiffer, 1849.

Helicina tenuis Pfeiffer, 1849; Proc. Zool. Soc. London (1848): 124-125 — Von Martens, 1890; Biol. Cent. Amer.: 34-35 — Fischer & Crosse, 1893: 416; pl. 56, figs. 101b, 2-2b, 3-3b (shell) — Von Martens, 1901; Biol. Cent. Amer.: 604 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 302-303; pl. 60, figs. 15-23, 25 (shell) — H. B. Baker, 1922; Occ. Pap. Mus. Zool. Univ. Mich., (186): 35-36 — Pilsbry, 1926a: 339 — Von Martens, 1901; Biol. Cent. Amer.: 605 — Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 12, 15, 32 — Van der Schalie, 1940; Occ. Pap. Mus. Zool. Univ. Mich., (413): 6, 9, 10 — Haas, 1949; Nautilus, 62: 137, 138 — Thompson, 1957; Nautilus, 70: 100 — Bequaert, 1957; Bull. Mus. Comp. Zool., 115: 207.

Helicina (Tenuis) tenuis tenuis Pfeiffer. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 50; pl. III, fig. 7; pl. IV, fig. 14 (radula).

Helicina tenuis tenuis Pfeiffer. Thompson, 1967; Bull. Fla. St. Mus., 11: 228-229.

Helicina vernalis Morelet, 1849; Test. Noviss., I:20 — Sowerby, 1866; Thes. Conch., 3: 288; pl. 273, fig. 273 (shell) — Reeve, 1874; Conch. Icon., Helicina: pl. 13, fig. 110 (shell) — Wagner, 1905; Denksch. Kaiserli. Akad…..: 233-234; pl. XIII, figs. 13a-13c (shell).

Helicina chiapensis Pfeiffer, 1856 — Sowerby, 1866; Thes. Conch., 3: pl. 272, figs. 255-257 (shell) — Reeve, 1874; Conch. Icon., Helicina: pl. 13, fig. 110 (shell).

Helicina tenuis chiapensis Pfeiffer. Pilsbry, 1892: 339.

?Helicina lindeni Tristram, 1862: 5 — Sowerby, 1866; Thes. Conch., 3: 288; pl. 272; figs. 255-257 (shell) — Bequaert & Clench, 1933; Pub. Carnegie Inst. Wash., (431): 543.

Helicina (Oligyra) lindeni Tristram. Fischer & Crosse, 1893: 416-420; pl. 56, figs. 1-3 (shell).

Helicina tenuis lindeni Pfeiffer. Hinkley, 1920; Nautilus, 34: 49, 52.

Helicina vernalis verapazensis Wagner, 1905; Denksch. Kaiserli. Akad. …: 234; pl. 13, fig. 14 (shell).

Helicina teunis pitieri Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 303-304; pl. 60, fig. 24 (shell).

Helicina (Tristramia) tenuis Pfeiffer. Richling, 2004; Malacologia, 45: 254-271; figs. 54-61 (shell); fig. 62 (operculum); fig. 63 (radula); figs. 64, 65 (reproductive system).

TYPE LOCALITIES — Helicina tenuis: Yucatan; lectotype BMNH 20010496 (Richling, 2004). Helicina vernalis: Petenensis Sylvas, Dept. Petén, Guatemala; lectotype BMNH 1893.2.4.1991 (Fischer & Crosse, 1893). Helicina chiapensis: Chiapas, Mexico; syntypes ZMB 65624. Helicina lindeni: Mexico. Helicina tenuis pittieri: Rio de los Plataneros S of Puerto Jimenez, Peninsula de Oso, Costa Rica (08º31’30” N, 83º18 W); holotype ZMB 103241. Helicina vernalis verapazensis: Verapaz, Guatemala.

DISTRIBUTION — Panama north to Guerrero, Mexico on the Pacific coast, and Veracruz on the Gulf of Mexico coast. Most commonly encountered at lower elevations below 1500 m alt. PANAMA: Barro Colorado Island (Pilsbry, 1930). COSTA RICA: numerous localities. HONDURAS, Dept. Colón: 2.6 km SW of La Brea (15º45’39” N, 86º00’08” W). Dept. Olancho: vicinity of Magua Cave, 15 km SSW of Guelaco (14º56.5’ N, 86º07.5’ W). EL SALVADOR, Dept. Ahuachapán: 6 km W of Atiquizaya, on rd. to Ahuachapán. GUATEMALA: numerous localities. CAMPECHE: 16.4 km E of Escarciga. CHIAPAS: 15 1. km W of San Cristobal, 2669 m alt.; 18.3 km N of Tuxtla Gutierrez, 1372 m alt.; 12.9 km N of Tuxtla Gutierrez, 1158 m alt.; 4.8 km SSE of Tuxtla Gutierrez, 822 m alt.; 7.5 km NNE of Huixtla, 183 m alt.; 21.3 km NW of Huixtla, 300 m alt.; 44.4 km NW of Ocozocoautla, 610 m alt.; 24.5 km NW of Ocozocoautla, 823 m alt.; 34.1 km E, 16.4 km S of Comitan, 1524 m alt.; Ruins of Palenque. GUERRERO: 1 km E of Petaquillas, 1158 m alt.; 2.2 km NNE of Mazatlán, 1475 m alt.; limestone hill 1 km NW of Naranjito, 675 m alt. (18º05’03” N, 101º50’45” W). OAXACA: Lagunas, 259 m alt.; limestone ridge 4 km W of Cuautemoc, 100 m alt. (17º05’56” N, 94º54’25” W); limestone knoll 13 km ENE of Sarabia, 125 m alt. (17º05’54” N, 94º56’34” W). TABASCO: 3 km N of Vicente Guerrero, 160 m alt. (17º39’09” N, 92º56’00” W); 6.8 km W of Teapa. VERACRUZ: 5 km ENE of Cuautemoc, Oaxaca, 75 m alt. (17º06’59” N, 94º56’34” W); 7 km S, 7 km E of Catamaco, 350 m alt.; Laguna Encantada; limestone knoll 2 km SW of Plan Arroyo (17º14’15” N, 94º37’36” W).

The above records are from Richling, 2004. The following records are given by other authors.

GUATEMALA, Dept. Alta Verapaz: Coban; Cubilguitz (Von Martens, 1890). Dept. Baja Verapaz: Panzos; Chacoj; San Juan; Purula (Von Martens, 1890). Dept. Quetzaltenango; Cerro Zunil; San Isidro; El Reposa; Zapote (Von Martens, 1890). Dept. Totonicapan: Totonicapam Mountains (Von Martens, 1890). CHIAPAS: El Real, 600 m alt.; Monte Libano, 600 m alt. (Bequaert, 1957; Bull. Mus. Comp. Zool., 115). TABASCO: San Juan Bautista; Teapa (Von Martens, 1890); Poana (Von Martens, 1901); 0.5-1.0 mi. E of Teapa (Thompson, 1957). VERACRUZ: Soledad (Von Martens, 1890).

Helicina (Tristramia) trossula Morelet, 1849

Helicina trossula Morelet, 1849; Test. Noviss., I: 19 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 311-312; pl. 62, figs. 10-14 (shell).

Helicina flavida (in part). Von Martens, 1890; Biol. Cent. Amer.: 39.

TYPE LOCALITY — Petén, Guatemala.

DISTRIBUTION — GUATEMALA: known only from the type locality.

Helicina (Tristramia) turbinata Pfeiffer, 1848

Helicina turbinata Pfeiffer, 1848; Zeitschri. Malak., 5: 87 — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 308-309; pl. 61, figs. 20-25 (shell) — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 781.

Helicina zephyrina Menke. Von Martens, 1890; Biol. Cent. Amer.: 30-32 (in part).

Helicina zephyrina var. excavato-angulata Von Martens, 1890; Biol. Cent. Amer.: 31.

TYPE LOCALITIES — Helicina turbinata: Jalapa, Veracruz, Mexico. Helicina zephyrina var. excavato-angulata: Veracruz.

DISTRIBUTION — VERACRUZ: Antigua; Misantla; Mirador (Pilsbry, 1903); Atoyac; Cordoba; Veracruz (Wagner, 1910).

Helicina (Tristramia) vanattae Pilsbry, 1910

Helicina vanattae Pilsbry, 1910; Proc. Acad. Nat. Sci. Phila., 61 (1909): 540-541 (not figured).

Helicina (Tristramia) chysocheila vanattae Pilsbry. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51 — Correa-Sandoval, Gutierrez & Reza, 1998; Acta Zool. Mex., 73: 13 — Correa-Sandoval & Castro, 2002; Acta Zool. Mex., (86): 235.

TYPE LOCALITY — On the sides of the canyon below Los Canoas, San Luís Potosí. Holotype ANSP 99025.

DISTRIBUTION — SAN LUÍS POTOSÍ: eastern part of state; sides of the highest peak S of Mecos Falls; Cascadas Micos (Sierra Colmena), 240 m alt. (22º06’35” N, 99º09’44” W); Carr. Cd. Valles-Agua Buena km 48, 900 m alt. (21º52’55” N, 99º22’06” W); Agua Buena, 3 km W of “Rincón Viborero”, 440 m alt. (21º57’33” N, 99º22’37” W); Carr. Río Verde-San Luís Potosí, km post 169 (21º59’30” N, 100º11’50” W); Las Cascadas, Tamasopo, (21º56’05” N, 99º25’00” W); Cueva “El Salitre”, Xilitla, numerous loclities in the region; Huichihuayanes (21º28’32” N, 98º58’41” W) (Corre — Sandoval, et al., 1998). Numerous localities in southern TAMAULIPAS (Correa-Sandoval & Castro, 2002).

Helicina (Tristamia) zephyrina zephyrina Duclos, 1833

Helicina zephyrina Duclos, 1833; in Guérin’s Mag. Zool.: 21 — Sowerby, 1866; Thes. Conch., 3: 288; pl. 273, figs. 266-269 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 30-31 (in part) — Fischer & Crosse, 1893: 407; pl. 5, figs. 10-10c, 11 (shell) — Von Martens, 1901; Biol. Cent. Amer.: 603 — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 782 — Correa-Sandoval, Gutierrez & Reza, 1998; Acta Zool. Mex., (73): 13 — Correa-Sandoval , 2000; Acta Zool. Mex., (79): 8 — Correa-Sandoval & Castro, 2002; Acta Zool. Mex., (86): 235.

Helicina (Tristamia) zephyrina zephyrina Duclos. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51; pl. 3, fig. 9; pl. 4, fig. 13 (radula) — H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 32-33; pl. 6 (female reproductive anatomy).

Helicina sandozi Shuttleworth, 1852; in Bern Mittheil.: 303 — Neubert & Gosteli, 2005; Contr. Nat. Hist., 5: 16; pl. 9, fig. 2 (not reported since its original description; a nomen oblitum).

Helicina behrendti Pfeiffer, 1862; Malak. Blätt., 8: 173; pl. 3, figs. 14-15 (shell).

TYPE LOCALITIES — Helicina zephyrina: “Vera Cruz”. Helicina sandozi: “Mexico”. Syntypes: NMBE 19039/1. Helicina behrendti: not stated.

DISTRIBUTION — 0AXACA: Tustepec [Tuxtepec] (Von Martens, 1901). SAN LUÍS POTOSÍ: numerous localities in eastern part of state (Correa-Sandoval, et al, 1998); 3 km E of Antiguo Tamuín, 70 m alt. (21º57’04” N, 98º46’50” W); 5 km SE of Tampamolón, 170 m alt. (21º34’23” N, 98º49’28” W); 5 km SW of San Martín, 400 m alt. (21º21’57” N, 98º42’06” W); 2 km N of Huichihuayán, 250 m alt. (21º30’00” N, 98º59’12” W); Carr. 15 km SW of Tamazunchale, 140 m alt. (21º12’40” N, 98º51’34” W); Vega Larga, 5 km SW of Tamazunchale, 120 m alt. (21º14’23” N, 98º50’31” W); Las Cascadas, Tamasopo (21º56’05” N, 99º25’00” W); Río Gallinas, Ejido El Carpintero (21º54’08” N, 99º15’47” W); Xilitla (21º22’55” N, 98º59’44” W); Los Ciruelos (21º18’02” N, 98º49’49” W); Barrio San Rafael, Río Moctezuma, Tamazunchale (21º15’21” N, 98º48’56” W); Tamazunchale (21º15’21” N, 98º48’09” W) (Correa-Sandoval, et al, 1998). TAMAULIPAS: numerous localities in southern part of state (Correa-Sandoval & Castro, 2002); Tampico (Hinkley, 1907). VERACRUZ: numerous localities in northern part of state (Correa-Sandoval, 2000); Jalapa, Mirador; Cordoba; Tejeria; Huatusco (Von Martens, 1890); Texolo (Pilsbry, 1903).

Helicina (Tristramia) zephyrina deppeana Von Martens, 1863

Helicina deppeana Von Martens, 1863; Monatsb. König. Preuss. Akad. Wiss. Berlin: 540 — Sowerby, 1866; Thes. Conch., 3: 298; pl. 272, figs. 264-265 (shell) — Von Martens, 1890; Biol. Cent. Amer.: 52; pl. 1, figs. 7-8 (shell) — Wagner, 1910; in Martini & Chemnitz, Syst. Conch. Cab., Helicinidae: 309-310; pl. 62, figs. 1-3 (shell).

Helicina (Tristramia) zephyrina deppeana Von Martens. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

TYPE LOCALITY — Mexico.

DISTRIBUTION — OAXACA: Yalalag, south of Villa Alta (Von Martens, 1890). VERACRUZ: Jalapa; Soledad (Von Martens, 1890).

Helicina (Tristramia) zephyrina dientensis Pilsbry, 1903

Helicina zephyrina dientensis Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 782 (no figure given).

Helicina zephyrina dientensis Pilsbry. H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 51.

TYPE LOCALITY — Diente, near Monterrey, Nuevo León, Mexico. Holotype ANSP 77238.

DISTRIBUTION — NUEVO LEÓN: known only from the type locality.

Genus Alcadia Gray, 1840

TYPE SPECIES — Helicina major Gray, 1824.

DISTRIBUTION — The West Indies and Central America.

TAXONOMY — Richling (2003) recognizes three subgenera. Alcadia s. s. and Idesa H. Adams. & A. Adams, 1856, are confined to the West Indies. Microaladia is endemic to Central America.

Subgenus Microalcadia Richling, 2004

Microalcadia Richling, 2004; Malacologia, 45: 370.

TYPE SPECIES — Helicina hojarasca Richling, 2004.

DISTRIBUTION — Costa Rica.

TAXONOMY — Three species are referred to the subgenus.

Alcadia (Microalcadia) boeckeleri (Richling, 2001)

Helicina boeckeleri Richling, 2001; Schriften zur Malak.: 6-7; figs. 9 (operculum), 10-11, 12B (shell).

Alcadia (Microlcadia) boeckeleri (Richling). Richling, 2004; Malacologia, 45: 374-377; figs. 257-261 (shell), fig. 262 (operculum), fig. 263 (distribution).

TYPE LOCALITY — Primary forest, Parqué Nacional Guanacaste, about 10 km S of Santa Cecilia, Volcán Orosí, near field station Pitilla, Guanacaste Prov., Costa Rica; 700 m alt. (10º59’18” N, 85º25’34” W). Holotype: UCR-INBio 3404980.

DISTRIBUTION — COSTA RICA: known only from the immediate vicinity of the type locality.

Alcadia (Miscroalcadia) hojarasca (Richling, 2001)

Helicina hojarasca Richling, 2001; Schriften zur Malak.: 5-6; fig. 6 (operculum), 7-8, 11A (shell).

Alcadia (Microalcadia) hojarasca (Richling). Richling, 2004; Malacologia, 45: 370-374; figs. 249-252 (shell), fig. 253 (operculum), fig. 254 (radula), fig. 255 (female reproductive system), fig. 256 (distribution).

TYPE LOCALITY — Cordillera de Tilarán, about 9 km N of Santa Elena, near Mirador Gerardo, Guanacaste Province, Costa Rica, 1450 m alt. (10º22’19” N, 84º48’25” W). Holotype UCR-INBio 3404389.

DISTRIBUTION — COSTA RICA: in addition to the type locality the species has been recorded from one other locality. Puntarens Prov: Zona Protectora Arenal-Monteverde, 1500-1650 m alt. (10º18’08” N, 84º47’41” W).

Alcadia (Microalcadia) exigua (Pfeiffer, 1849)

Helicina exigua Pfeiffer, 1849; Proc. Zool. Soc. London (1848): 121.

?Alcadia (Micoalcadia) exigua (Pfeiffer). Richling, 2004; Malacologia, 45: 374.

TYPE LOCALITY — Honduras.

DISTRIBUTION — Central America. In 1849 Honduras included most of the Caribbean coast of Central America from the Yucatan Peninsula south to Costa Rica and Panama.

Genus Lucidella Swainson, 1840

Lucidella Swainson, 1840, Richling, 2004; Malacologia, 45: 194, 330.

TYPE SPECIES — Helix aureola Férussac, 1822.

DISTRIBUTION — South Florida, the West Indies, and the Caribbean region of the South American mainland from French Guyana north to Veracruz, Mexico.

TAXONOMY — Four subgenera are recognized. Lucidella s.s. and Poeniella H. B. Baker, 1923 are confined to the West Indies region. Lidsleya Chitty, 1857 is found in Jamaica and on the South American mainland (H. B. Baker, 1922b). Poenia H. & A. Adams, 1856, is found on the mainland from French Guyana north to Mexico and on some near-by mainland islands in the Caribbean region.

Subgenus Poenia H. Adams & A. Adams, 1856

Poenia H. Adams & A. Adams, 1856: 304 (type species: Helicina unidentata Pfeiffer, 1847).

Perenna Guppy, 1867: 260 (type species: Helicina lamellosa Guppy, 1867).

DISTRIBUTION — French Guyana and coastal islands north to Veracruz, Mexico.

TAXONOMY — Five species are recognized. One is widely distributed on the mainland, one occurs on Roatán Island, one occurs on Swan Island (Lucidella pilsbryi Clapp, 1914), one occurs on Cuba (Lucidella granum Pfeiffer, 1856), and one occurs on Grand Cayman Island (Lucidella caymanensis Pilsbry, 1930).

Lucidella (Poenia) lirata (Pfeiffer, 1847)

Helicina lirata Pfeiffer, 1847; Zeitschr. Malak., 4: 150 — Pfeiffer, 1850; in Martini & Chemnitz, Syst. Conch. Cab., Helicina: 14-15; pl. 9, figs. 14-17 (shell) — Strebel, 1873: 21; pl. 1a, fig. 8; pl. 2, fig. 8 (shell) — Von Martens, 1891: 41-42, 332; pl. 1, fig. 18 (shell).

Helicina (Poenia) lirata Pfeiffer. Fischer & Crosse, 1893: 397-399.

Lucidella lirata (Pfeiffer). Wagner, 1911; in Martini & Chemniz, Syst. Conch. Cab., Lucidella: 341; pl. 68, figs. 5-7 (shell) — Hinkley, 1920; Nautilus, 34: 41, 49. 52 — Pilsbry, 1926; Proc. Acad. Nat. Sci. Phila., 78: 59, 71 — Pilsbry, 1926; Proc. Acad. Nat. Sci. Phila., 78: 127 — Pilsbry, 1930; Proc. Acad. Nat. Sci. Phila., 82: 339 — Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 12, 14-16, 33 — Richards, 1938; Proc. Amer. Philos. Soc., 79: 176 — Bequaert, 1957; Bull. Mus. Comp. Zool., 115: 208 — Basch, 1959; Occ. Pap. Mus. Zool. Univ. Mich., (612): 8 — Haas & Solem, 1960; Nautilus, 73: 130 — Branson & McCoy, 1963; Nautilus, 76: 102-103 — Thompson, 1967; Bull. Fla. St. Mus., 11: 229 — Thompson, 1982: fig. 13 (radula), figs. 27-28 (embryonic shell) — Peréz & Lopéz, 2002: 47-49 — Richling, 2004; Malacologia, 45: 377-386; figs. 264-267 (shell), fig. 268 (operculum), fig. 269 (radula), fig. 270 (female reproductive anatomy), fig. 273 (distribution in Costa Rica).

Lucidella (Poenia) lirata (Pfeiffer). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 54-55; pl. 3, fig. 5; pl. 5, fig. 21 (radula) — H. B. Baker, 1922b; Occ. Pap. Mus. Zool. Univ. Mich., (186): 36 — H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 33-34; pl. 2, figs. 9-11 (reproductive anatomy) — Bequaert & Clench, 1933; Pub. Carnegie Inst. Wash., (431): 543.

Helicina unidentata Pfeiffer, 1849: 125 — Sowerby, 1866; Thes. Conch., 3: 281; pl. 268, fig. 87 (shell) — Reeve, 1874; Conch. Icon., Helicina: pl. 14, fig. 122 (shell) — Ancey, 1886: 254.

Helicina lirata var unidentata Pfeiffer. Von Martens, 1891 41, 607.

Helicina (Perena) lamellosa Guppy, 1867: 260, pl. 10, fig. 4 (shell).

Lucidella lirata lamellosa Wagner, 1911; in Martini & Chemnitz, Syst. Conch. Cab., Lucidella: 341-342; pl. 68, fig. 4 (shell).

Helicina rusticella Morelet, 1849; Test. Noviss., I: 21.

Helicina lirata var. rusticella Morelet. Von Martens, 1891: 41 — Fischer & Crosse, 1893: 397-399 — Von Martens, 1900: 607.

Helicina semistriata Sowerby, 1866; Thes. Conch., 3: 281; pl. 268, fig. 86 (shell) — Tate, 1870: 159.

Helicina lirata var. semistriata Sowerby. Von Martens, 1891: 41.

TYPE LOCALITIES — Helicina lirata: Yucatan, Mexico; primary type destroyed (Boss & Jacobson, 1974). Helicina unidentata: Honduras; type probably lost (Boss & Jacobson, 1974: 37). Helicina rusticella: Isla de Carmen, Mexico; syntype BMNH 1893.2.4. Helicina semistriata: not given; types destroyed (Bosse & Jacobson, 1974). Helicina lamellosa: Gulf of Paria, Trinidad; syntype BMNH 1874.10.30.12.

DISTRIBUTION — Widely distributed along the Caribbean Coast from French Guiana to central Veracruz, Mexico, and on coastal islands. Central American and Mexican records follow. PANAMA: Tabernillo, Canal Zone; nr. Darien; Juan Minas; Panama City; Taboga Island (Pilsbry, 1926a); Bocas del Toro (Von Martens, 1891). COSTA RICA: numerous localities in Limón Prov. and in Puntarens Prov. below 200 m alt. (Richling, 2004). NICARAGUA, Depts. Boaco, Estelí, Matagalpa, Rivas and Rio San Juan (Pérez & López, 2002). Dept. Matagalpa: 4.5 km S of Matagalpa, 1200 m alt. (Richling, 2004; Malacologia, 45). HONDURAS: Roatán Island (Richards, 1938); Utila Island (Pilsby, 1891). GUATEMALA, Dept. Izabal: Jocola (Hinkley, 1920). Dept. Alta Verapaz: Chamá (Hinkley, 1920). Dept. Petén: Tikal (Basch, 1959). BELIZE, Cayo District: Rio Frio Cave (Haas & Solem, 1960). QUINTANA ROO: 4 mi. E of Xpujil; 7.1 m. NNW of Xiatil (Thompson, 1967). YUCATAN: Chichen Itza (Bequaert & Clench, 1933); Labna (Pilsbry, 1901). CAMPECHE: Ciudad del Carmen (Branson & McCoy, 1963); numerous localities (Thompson, 1967). TABASCO: Teapa; San Juan Bautista (Von Martens, 1891); 0.5-1.0 mi. E of Teapa (Thompson, 1957). CHIAPAS: Selva Lacondona, Laguna Ocotal, 950 m alt.; Laguna Ocotal to El Censo, 1000 m alt. (Bequaert, 1957). YUCATAN: Labna (Pilsbry, 1891). VERACRUZ: Atoyac (H. B. Baker, 1928).

Lucidella (Poenia) midyetti Richards, 1938

Lucidella midyetti Richards, 1938; Proc. Amer. Philos. Soc., 79: 175-176; pl. 3, figs. 3-4.

TYPE LOCALITY — Between Coxen Hole and French Harbor, Roatán Island, Honduras. Holotype ANSP 170021.

DISTRIBUTION — HONDURAS: known only from Roatán Island.

Lucidella (Poenia) pilsbryi pilsbryi Clapp, 1914

Lucidella pilsbryi Clapp, 1914; Nautilus, 27: 100-101; pl. 6, figs. 6-7 (shell) — Pilsbry, 1930; Proc. Acad. Nat. Sci. Phila., 82: 243; pl. 15, figs. 2, 2a (shell).

TYPE LOCALITY — Swan Island, Bay of Honduras. Holotype MCZ 22890.

DISTRIBUTION — HONDURAS: known only from the type locality.

Lucidella (Poennia) pilsbryi indecora Pilsbry, 1930

Lucidella (Poennia) pilsbryi indecora Pilsbry, 1930; Proc. Acad. Nat. Sci. Phila., 2: 243; pl. 17, fig. 5.

TYPE LOCALITY — Little Swan Island, at the western third a short distance from the north shore. Holotype ANSP 150881.

DISTRIBUTION. HONDURAS: known only from the type locality.

Genus Schasicheila Shuttleworth, 1852

Schasicheila Shuttleworth, 1852; in Bern Mittheil.: 301 — Von Martens, 1890; Biol. Cent. Amer.: 43, 608 — Wagner, 1911; in Martini & Chemnitz, Syst. Conch. Cab., Schasicheila: 351 — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 56-57 — H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 36 — Richling, 2002: 408-409.

TYPE SPECIES — Helicina nicoleti Shuttleworth, 1852.

DISTRIBUTION — Eastern Mexico from Tamaulipas south to Guatemala.

TAXONOMY — The genus is divided into three subgenera and includes ten species and two subspecies.

Subgenus Atoyac H. B. Baker, 1928.

Atoyac H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 36.

TYPE SPECIES — Helicina alata Pfeiffer, 1849.

DISTRIBUTION — Northeast Mexico from Nuevo León, southern Tamaulipas, sotheastern San Luis Potosi and Veracruz.

TAXONOMY — Three species are recognized.

Schasicheila (Atoyac) alata (Pfeiffer, 1849)

Helicina alata Pfeiffer, 1849; Proc. Zool. Soc. London (1848): 87.

Schazichila alata (Pfeiffer). Strebel, 1973: 23-24; pl. 4, fig. 7 (shell).

Schasicheila alata (Pfeiffer). Von Martens, 1890; Biol. Cent. Amer.: 43 — Von Martens, 1901; Biol. Cent. Amer.: 608 — Wagner, 1911; in Martini & Chemnitz, Syst. Conch. Cab., Schasicheila: 353; pl. 69, figs. 20-21 (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57 — Richling, 2004; Malacologia, 45: 408-409; figs. 325-327 (shell), fig. 328 (female reproductive anatomy).

Schasicheila (Atoyac) alata Pfeiffer. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 39; pl. 3, fig. 16 (male reproductive anatomy); pl. 4, figs. 19-20 (female reproductive anatomy).

TYPE LOCALITY — Cordova [Cordoba], Veracruz, Mexico.

DISTRIBUTION — CHIAPAS: Monte Libano, 600 m alt. (Bequaert, 1957; Bull. Mus. Comp. Zool., 115). VERACRUZ: Mizantla (Strebel, 1873); Mirador; San Cristobal; Atoyac; Jalapa (Von Martens, 1890); Orizaba (Von Martens, 1901).

Schasicheila (Atoyac) fragilis Pilsbry, 1899

Schasicheila fragilis Pilsbry, 1899; Proc. Acad. Nat. Sci. Phila., 51: 391 — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 782-783; pl. 51, figs. 7, 7a (shell) — Wagner, 1911; in Martini & Chemnitz, Syst. Conch. Cab., Schasicheila: 353; pl. 69, figs. 20-21 (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57 — Correa-Sandoval & Castro, 2002; Acta Zool. Mex., (86): 235.

Schasicheila (Atoyac) fragilis Pilsbry. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 40; pl. 5, figs. 30-31 (operculum), fig. 32 (shell sculpture).

TYPE LOCALIT — Diente, near Monterrey, Nuevo Leon, Mexico. Holotype ANSP 77237.

DISTRIBUTION — TAMAULIPAS: Victoria-Gomez Farias Hwy, Rio Frio (23º00’00” N, 99º05’30” W); La Tapona, Tula (23º08’31” N, 99º58’16” W); Ejida Manuel Avila Comacho (23º40’00” N, 98º59’18” W); Rancho El Armadillo (23º45’34” N, 99º05’10” W); Ejido Conrado Castillo (23º27’12” N, 99º27’34” W) (Correa-Sandoval & Castro, 2002).

Schasicheila (Atoyac) xanthia Pilsbry, 1909

Schazicheila xanthia Pilsbry, 1909: 540; text-fig. 1 (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57 — Correa-Sandoval, Gutierrez & Reza, 1998; Acta Zool. Mex., (73): 13.

Schasicheila (Atoyac) xanthia Pilsbry. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 36.

TYPE LOCALITY — Canyon below Los Canoas, San Luís Potosí. Holotype ANSP 99024.

DISTRIBUTION — SAN LUÍS POTOSÍ: Cueva El Salitre, 6 km SW of Xilitla, 450 m alt. (21º22’55” N, 98º57’53” W) (Correa-Sandoval, et al, 1998).

Subgenus Necaxia H. B. Baker, 1928

Necaxia H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 36.

TYPE SPECIES — Helicina minuscula Pfeiffer, 1859.

DISTRIBUTION — Guatemala north to San Luís Potosí.

TAXONOMY — A single species is recognized.

Schasicheila (Necaxia) minuscula (Pfeiffer, 1859)

Helicina minuscula Pfeiffer, 1859; Proc. Zool. Soc. London: 29.

Schasicheila minuscula (Pfeiffer). Fischer & Crosse, 1893: 452; pl. 54, figs. 7-7b (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57 — Correa-Sandoval, Gutierrez & Reza, 1998; Acta Zool. Mex., (73): 13 — Correa-Sandoval, 2000; Acta Zool. Mex., (79): 8.

Schasichila minuscula (Pfeiffer). Von Martens, 1901; Biol. Cent. Amer.: 608-609.

Schasicheila (Necaxia) minuscula (Pfeiffer). H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 34-38; pl. 3, fig. 15 (male reproductive anatomy); pl. 4, figs. 17-18 (female reproductive anatomy); pl. 5, figs. 28 (radula).

Schasicheila “minima” (“Pfeiffer”). Strebel, 1880: 98; pl. 3, fig. 6 (shell).

TYPE LOCALITY — Misantla, Veracruz (H. B. Baker, 1928).

DISTRIBUTION — GUATEMALA, Dept. Alta Verapaz: Chama (H. B. Baker, 1928). SAN LUÍS POTOSÍ: Tamazunchale, 170 m alt. (21º15’21” N, 98º28’09” W); Cueva La Salitre, 6 km W of Xilitla, 830 m alt. (21º23’10” N, 99º03’56” W); 0.3 km NW Las Posas, 600 m alt. (21º24’38” N, 99º00’15” W) (Correa-Sandoval, et al, 1998). VERACRUZ: Misantla, 410 m alt. (19º56’ N, 97º44’ W); Necaxa, 2625-4925 m alt. (H. B. Baker, 1928); (numerous localities in northern Veracruz (Correa-Sandoval, 2000).

Subgenus Schasicheila Shuttleworth, 1852

DISTRIBUTION — Eastern Mexico from Tamaulipas south to Alta Verapaz, Guatemala.

TAXONOMY — Nine species and two subspecies are recognized.

Schasicheila (Schasicheila) hidalgoana Dall, 1897

Schasicheila hidalgoana Dall, 1897; Nautilus, 11: 62 — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 783-784; pl. 51, figs. 8, 8a (shell) — Hinkley, 1907; Nautilus, 21: 71 — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57; pl. 5, figs. 18, 20 (radula) — H. B. Baker, 1926; Proc. Acad. Nat. Sci. Phila., 76: 49-50; pl. 8, figs. 24-26 (reproductive anatomy) — Correa-Sandoval, Gutierrez & Reza, 1998; Acta Zool. Mex., (73): 13 — Correa-Sandoval, 2000; Acta Zool. Mex., (79): 8 — Correa-Sandoval & Castro, 2002; Acta Zol. Mex., (86): 235.

Schasicheila (Schasicheila) misantlensis Fischer & Crosse. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 41.

TYPE LOCALITY — Encarnacion, Hidalgo, Mexico. Holotype in the USNM.

DISTRIBUTION — SAN LUÍS POTOSÍ: numerous localities; (Correa-Sandoval, et al, 1998). TAMAULIPAS: canyon 4 mi. W of Cd. Victoria (Pilsbry, 1903); Ejido Filipe Angeles (23º30’00” N, 98º24’07” W); Ejido San Antonio, Rio Chihue (23º33’55” N, 99º20’02” W); Ejido El Olmo, Hidalgo (24º13’36” N, 99º24’49” W). (Correa-Sandoval & Castro, 2002). VERACRUZ: Rio Cazones, Cazones (20º37’17” N, 97º24’13” W); La Ordeña, Papantla (20º29’43” N, 97º18’17” W) (Correa-Sandoval, 2000).

Schasicheila (Schasicheila) hinkleyi Pilsbry, 1919

Schasicheila hinkleyi Pilsbry, 1919; Proc. Acad. Nat. Sci. Phila., 71: 221; fig. 9 (shell), 10 (operculum) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57.

Schasicheila (Schasicheila) hinkleyi Pilsbry. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 37.

TYPE LOCALITY — Chama, [Dept. Alta Verapaz], Guatemala. Holotype in the ANSP.

DISTRIBUTION — GUATEMALA: known only from the type locality.

Schasicheila (Schasicheila) misantlensis Fischer & Crosse, 1893

Schasichila pannucea misantlensis Fischer & Crosse, 1893: 449; pl. 54, figs. 5b-d (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57.

Schasicheila (Schasicheila) misantlensis Fischer & Crosse. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 41-43.

TYPE LOCALITY — Misantla, [Veracruz], Mexico.

DISTRIBUTION — VERACRUZ: Neaxa, 2215-5500 ft. alt. (H. B. Baker, 1918).

Schasicheila (Schasicheila) nicoleti Shuttleworth, 1852

Shasicheila nicoleti Shuttleworth, 1852; in Bern Mittheil.: 302 — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57. Correa-Sandoval & Castro, 2002; Acta Zool. Mex., (86): 235 — Neubert & Gosteli, 2005; Contr. Nat. Hist., 5: 15; pl. 10, fig. 2.

Helicina nicoleti (Shuttleworth). Reeve, 1874; Conch. Icon., Helicina: pl. 19, fig. 109.

Schasichila nicoleti (Shuttleworth). Von Martens, 1890; Biol. Cent. Amer.: 43.

Schasicheila (Schasicheila) nicoleti Shuttleworth. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 40-41.

TYPE LOCALITY — Cordova [Cordoba], Veracruz, Mexico.

DISTRIBUTION — TAMAULIPAS: Los Angeles, Sierra Tamaulipas (23º32’37” N, 98º29’39” W); Ranch El Carrizo, 25 km NE of Cd. Victoria (23º47’51” N, 97º59’39” W); Ejido El Sabinito (23º34’39” N, 98º21’22” W); Ejido Conrado Castillo (23º57’12” N, 99º27’34” W); 53 km NE of Cd. Victoria (24º04’54” N, 98º51’22” W) (Correa-Sandoval & Castro, 2002). VERACRUZ: Cerro de Plumas, nr. Cordoba; Jalapa (Von Martens, 1990); Las Tortolas, 2650 ft. alt. (H. B. Baker, 1928).

Schasicheila (Schasicheila) palmeri Dall, 1905

Schasicheila palmeri Dall, 1905; Smiths. Misc. Coll., 48: 19-192, pl. 44, figs. 3, 5 (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57.

Schasicheila (Schasicheila) misantlensis Fischer & Crosse. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 41.

TYPE LOCALITY — Alverez Mountains, San Luís Potosí, Mexico; 7900 ft. alt. Holotype USNM 110397.

DISTRIBUTION — SAN LUÍS POTOSÍ: San Dieguito (Dall, 1905).

Schasicheila (Schasicheila) pannucea (Morelet, 1849)

Helicina pannucea Morelet, 1849; Test. Noviss., I: 21.

Schasicheila pannucea (Morelet). Sowerby, 1866; Thes. Conch., 3: pl. 269; figs. 68, 69 (shell) — Wagner, 1911; in Martini & Chemnitz, Syst. Conch. Cab., Schasicheila: 352; pl. 70, figs. 1-4 (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57 — Bequaert, 1957; Bull. Mus. Comp. Zool., 115: 207.

Schasicheila (Schasicheila) pannucea (Morelet). H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 42.

Schasichila pannucea (Morelet). Von Martens, 1890; Biol. Cent. Amer.: 43, 608 — Fischer & Crosse, 1893: 448; pl. 54, figs. 5, 5a (shell).

Helicina alata (Menke). Reeve, 1874; Conch. Icon., Helicina: pl. 13, fig. 107 (shell).

TYPE LOCALITY — San Luís, Dept. Petén, Guatemala.

DISTRIBUTION — GUATEMALA, Dept. Alta Verapaz: Coban. Dept. Baja Verapaz: Senahu, N of Polochic Valley. Dept. Petén: San Luís (Von Martens, 1890). CHIAPAS: Monte Libano, 600 m alt.

Schasicheila (Schasicheila) pilsbryi Wagner, 1911

Schasicheila pilsbryi Wagner, 1911; in Martini & Chemnitz, Syst. Conch. Cab., Schasicheila: 352; pl. 70, figs. 9-11 (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57.

Schasicheila (Schasicheila) pilsbryi Wagner. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 37.

TYPE LOCALITY — Mexico or Guatemala.

DISTRIBUTION — Unknown.

Schazicheila (Schasicheila) vanattai vanattai Pilsbry, 1899

Schazicheila vanattai vanattai Pilsbry, 1899; Proc. Acad. Nat. Sci. Phila., 51: 391 — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 783; pl. 51, figs. 5, 5a (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57.

Schasicheila (Schasicheila) vannattai vannattai Pilsbry. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 36.

TYPE LOCALITY — Diente, near Monterrey, Nuevo Leon. Holotype in the ANSP.

DISTRIBUTION — NUEVO LEÓN: Santiago (Correa-Sandoval, 1993).

Schasicheila (Schasicheila) vannattai tricostata Pilsbry, 1903

Schasicheila vannattai tricostata Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 783; pl. 51, fig. 5 (shell) — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 57.

Schasicheila (Schasicheila) vannattai tricostata Pilsbry. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 37.

TYPE LOCALITY — Canyon 4 miles west of [Ciudad] Victoria, Tamaulipas. Holotype ANSP 85809.

DISTRIBUTION — TAMAULIPAS: known only from the type locality.

Schasicheila (Schasicheila) walkeri Hinkley, 1920

Schasicheila walkeri Hinkley, 1920; Nautilus, 34: 53 (unfigured).

TYPE LOCALITY — A blFLMNHf on the mountain north of Chama, Dept. Alta Verapaz, Guatemala. Holotype in the ANSP.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Subfamily VIANINAE Baker, 1922

The subfamily VIANINAE is distributed primarily in the West Indies. A single genus occurs in the study area.

Genus Pyrgodomus Crosse & Fischer, 1893

Pyrgodomus Crosse & Fischer, in Fischer & Crosse 1893: 440 — H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 43-46.

TYPE SPECIES — Helicina chryseis Tristram, 1861.

DISTRIBUTION — Pyrgodomus is widely distributed at lower and intermittent elevations on calcareous substrata from Tamaulipas and Guerrero south to Puntarenas Prov., Costa Rica.

TAXONOMY — Three species and one subspecies are recognized. The small size of the species and the paucity of adequate field surveys over much of this territory cause Pyrgodomus to be under-recorded. The genus is in critical need of review.

Pyrgodomus fischeri Pilsbry, 1930

Pyrgodomus fischeri Pilsbry, 1930; Proc. Acad. Nat. Sci. Phila., 82: 243-244; pl. 15, fig. 3 (shell).

TYPE LOCALITY — Honduras, Swan Island. Holotype ANSP 150868.

DISTRIBUTION — HONDURAS: known only from the type locality.

Pyrgodomus micordinus microdinus (Morelet, 1851)

Helicina microdina Morelet, 1851; Test. Noviss., II: 18 — Von Martens, 1890; Biol. Cent. Amer.: 39.

Helicina (Idesa) microdina Morelet. Fischer & Crosse, 1893: 438-439; pl. 56, fig. 9 (shell).

Eutrochatella (Artecallossa) microdina (Morelet). Wagner, 1908: 138; pl. 22, figs. 17-20 (shell).

Eutrochatella (Pyrgodomus) microdinus microdinus (Morelet). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 61.

Pyrgodomus micordinus microdinus (Morelet). H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 45-46 — Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 13, 33 — Richling, 2004; Malacologia, 45: 364-370; figs. 242-245 (shell), fig. 246 (radula), fig. 247 (female reproductive system), fig. 248 (Costa Rica distribution).

Helicina chryseis Tristram, 1862; Proc. Zool. Soc. London (1861): 5 — Von Martens 1891: 39; pl. 1, fig. 14 (shell) — Von Martens, 1900: 606.

Helicina (Pyrgodomus) chryseis Tristram. Fischer & Crosse, 1893: 440; pl. 56, fig. 6 (shell).

Eutrochatella mirodina chryseis (Tristram). Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 197 — Hinkley, 1920; Nautilus, 34: 52 — H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 61.

Pyrgodomaus microdinus chryseis (Tristram). H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 45-46.

TYPE LOCALITIES — Helicina microdina: Guatemala, [Dept. Verapaz}, Vera-paz, Guatemala. Lecotype BMNH 1893.2.3.1986. (Richling, 2004). Helicina chryseis: Guatemala, mountain forests of Vera Paz; location of the primary types are unknown.

DISTRIBUTION — Widely distributed at lower and intermittent elevations on calcareous substrata from Tamaulipas and Guerrero, Mexico south to Puntarenas Prov., Costa Rica. The genus Pyrgodomas consists of small-size species. The paucity of adequate field surveys over much of this territory cause the genus to be under-recorded. Numerous specimen lots of Pyrgodomus in the FLMNH are from Costa Rica, Nicaragua, Honduras, Guatemala, Belize and Mexico. GUATEMALA, Dept. Alta Verapaz: Chama (Pilsbry, 1920). MEXICO. Numerous specimen lots of Pyrgodomus in the FLMNH are from the states of Yucatan, Quintana Roo, Campeche, Tabasco. Chiapas, Oaxaca, Veracruz, San Luís Potosí, and Tamaulipas.

Pyrgodomus microdinus abditus H. B. Baker, 1928

Pyrgodomus microdina abditus H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 43-46; pl. 5, fig. 34 (shell), fig. 29 (radula); fig. 33 (operculum), pl. 4, fig. 21-24 (reproductive anatomy).

TYPE LOCALITY — Las Tortolas, Cordoba, Veracruz; 1300-3400 ft. alt. Holotype in the UMMZ.

DISTRIBUTION — VERACRUZ: Cordoba; Atoyac Gorge to Sumidero (H. B. Baker, 1928).

Pyrgodomus simpsoni (Ancey, 1886)

Trochatella simpsoni Ancey, 1886; Bull. Soc. Malac. France, 2: 235.

Pyrgodomus simpsoni (Ancey). Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 782; pl. 49, fig. 4 (shell).

Eutrochatela (Pyrgodomus) simpsoni (Ancey). H. B. Baker, 1922; Proc. Acad. Nat. Sci. Phila., 74: 61.

TYPE LOCALITY — Utila Island, Honduras.

DISTRIBUTION — HONDURAS: known only from the type locality.


Superfamily AMPULLARIOIDEA

Family AMPULLARIIDAE Gray, 1824

Pilidae Preston, 1915.

Ampullariidae Gray, 1824 — Cowie, 1997; Bulletin of Zoological Nomenclature, 54 (2) — Cowie & Thiengo, 2003; Malacologia, 45.

TYPE GENUS — Ampullaria Lamarck, 1799. Ampullaria is a junior synonym of Pila Röding, 1798. The family name Pilidae was based on the genus Pila. The International Commission on Zoological Nomenclature [ICZN] 1999a, Opinion 1913 ruled that Ampullariidae is the valid name for this family.

DISTRIBUTION — Freshwater in Tropical America, Africa and southeast Asia east to the Philippine Islands.

TAXONOMY — The taxonomy of this family is subjective and unstable. There is little agreement on the number of genera or subgenera, and the species level taxonomy is chaotic. Nearly all species were described on the basis of only the shell. In most instances only a single specimen was included in the original description. Frequently the locality of origin of type specimens was unknown or was only vaguely known. The result of this history is that there is very little agreement concerning how many valid species exist among the hundreds of names that have been proposed. Cowie & Thiengo (2003) recognize 140 neotropical species and subspecies as possibly valid among five indigenous genera. Their work represents a major effort to bring some order to this chaos. The following arrangement departs very little from their scheme.

Genus Marisa Gray, 1824

Marisa Gray, 1824; Philos. Mag. & Jour., 63: 276 — Cowie & Thiengo, 2003; Malacologia, 45: 49.

Ceratodes Guilding, 1828; Zool. Jour., 3: 537.

TYPE SPECIES — Marisa; Helix cornuarietis Linneaus, 1758 by subsequent designation of Gray, 1847. Ceratodes: Helix cornuarietis Linnaeus, 1758 by original designation.

DISTRIBUTION — South America, Central America.

TAXONOMY — Eight species have been described. Three are currently recognized. Marisa cornuaurietis (Linnaeus) is found in northern South America; M. planogyra Pilsbry is found in the Rio Parana system, and M. rotula (Mousson) is known from Colombia, Panama and Costa Rica.

Marisa rotula (Mousson, 1869)

Ampullaria rotula Mousson, 1869; Malac. Blätt., 16: 183 — Von Martens, 1899: 425; pl. 25, figs. 1, 1a, 1b.

Ceratodes rotula (Mousson). Mousson, 1873; Malac. Blätt., 16: 19.

Marisa rotula (Mousson). Pilsbry, 1933; Proc. Acad. Nat. Sci. Phila., 85: 71.

Marisa cornuarietis (Linnaeus). Cowie & Thiengo, 2003; Malacologia, 45: 51.

TYPE LOCALITY — Colombia, lower part of the Magdalena River. Syntypes ZMZ 525321.

DISTRIBUTION RECORDS — Colombia, Panama and Costa Rica. COSTA RICA (Von Martens, 1899).

Genus Pomacea Perry, 1812

Pomacea Perry, 1812; Arcana: unnumbered plate — Cowie & Thiengo, 2003; Malacologia, 45: 51.

Conchylium Cuvier, 1816: 426.

Limnopomus Dall, 1904; Jour. of Conch., 11: 52.

TYPE SPECIES — Pomacea: Pomacea maculata Perry, 1812, by original designation. Conchylium: Nerita urceus Müller, 1774. Limnopomus: Ampullaria columellaris Gould, 1848.

DISTRIBUTION — South America north to Tamaulipas along the east coast of Mexico, and to Colima along the Pacific coast; the Windward Island of the Lesser Antilles; Jamaica; Cuba; the southeastern United States.

TAXONOMY — Cowie & Thiengo (2003) include three subgenera. Only one occurs in Central America and Mexico.

Subgenus Pomacea Perry, 1812

DISTRIBUTION — Same as for the genus.

TAXONOMY — Cowie & Thiengo (2003) list 97 species in the subgenus Pomacea. Fourteen occur in the study area.

Pomacea auriformis (Reeve, 1856)

Ampullaria auriformis Reeve, 1856; Conchologica Iconica, 10: pl. 28; figs. 133a, b — Von Martens, 1899: 417.

Pomacea auriformis (Reeve). Pain, 1964; Jour. of Conch., 25: 225 — Cowie & Thiengo, 2003; Malacologia, 45: 57.

TYPE LOCALITY.— Honduras. Syntype BMNH 20020646.

DISTRIBUTION RECORDS — Unknown. When this species was described in 1856 Honduras included nearly the whole Caribbean Coast of Central America.

Pomacea belizensis (Crosse & Fischer, 1888)

Ampullaria belizensis Crosse & Fischer in Fischer & Crosse, 1888: pl. 45; figs. 2, 2a-2c — Crosse & Fischer, 1890; Jour. de Conchyl., 38: 110 — Fischer & Crosse, 1890; 231; pl. 48; figs. 9, 9a — Von Martens, 1899: 417.

Pomacea flagellata (Say). Pain, 1964; Jour. of Conch., 25: 227 — Cowie & Thiengo, 2003; Malacologia, 45: 58.

TYPE LOCALITY.— No locality given by Crosse & Fischer in 1888. Belize (Fischer & Crosse, 1890). Syntypes in MNHN.

DISTRIBUTION RECORDS — BELIZE: known only from the type locality.

Pomacea catamacensis (H. B. Baker, 1922)

Ampullaria patula catamacensis H. B. Baker, 1922; Occ. Pap. Mus. Zool. Univ. Mich., (106): 39; pl. 14, figs. 1-2, pl. 15, fig. 7.

Pomacea patula (H. B. Baker). Naranjo-Garcia & Garcia-Cubas, 1986; Ann. Inst. Biol., 56: 603 — Espinoza-Chávez & Martínez-Jerónimo, 2005; Veliger, 47: 213-217 (reproductive biology) — Cowie & Thiengo, 2003; Malacologia, 45: 59.

TYPE LOCALITY — Lago de Catamaco, Veracruz. Holotype: UMMZ 31850.

DISTRIBUTION RECORDS — VERACRUZ: known only from Lago de Catamaco

REMARKS — This species was described as a subspecies of Ampullaria patula Reeve, 1856, from New Grenada (= Colombia and Panama (see Cowie & Thiengo, 2003: 71). The name Ampullaria patula Reeve is a primary junior homonym of Ampullaria patula Lamarck, 1804 (Naticidae), and is not available for use. The identity of Reeve’s species from New Grenada is unresolved, but it has no bearing on the status of P. catamacensis.

Pomacea cerasum (Hanley, 1854)

Ampullaria cerasum Hanley, 1854: unnumbered page — Von Martens, 1899: 421; pl. 24, figs. 1-6.

Pomacea cerasum (Hanley). Cowie & Thiengo, 2003; Malacologia, 45: 59.

TYPE LOCALITY — Not given.

DISTRIBUTION RECORDS — TABASCO: Teapa (Von Martens, 1899: 421).

Pomacea conoidea (Von Martens, 1899)

Ampullaria conoidea Von Martens, 1899: 423; pl. 24, figs. 10, 11.

Pomacea conoidea (Von Martens). Cowie & Thiengo, 2003: 60.

TYPE LOCALITY — Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Pomacea costaricenana (Von Martens, 1899)

Ampullaria costaricana Von Martens, 1899: 418-419; pl. 24, figs 14-17.

Pomacea costaricana (Von Martens). Cowie & Thiengo, 2003: 60.

TYPE LOCALITY — Not given. No type designated.

DISTRIBUTION RECORDS — Von Martens (1899) gives the following locality records. NICARAGUA: Lago de Nicaragua. COSTA RICA, Puntarenas Prov.: Rio Saveyre, at Boca Culebra; Palmar, south of the Rio Grande de Terraba. PANAMA, Chiriqui Prov.: Chiriquí.

Pomacea cumingi cumingi (King & Broderip, 1831)

Ampullaria cumingii King & Broderip, 1831; Zool. Journal, 5: 332-349.

Pomacea cumingii (King & Broderip). Morrison, 1946; Smithson. Misc. Coll., 106: 6 — Morrison, 1952; Nautilus, 65: 105-106 — Cowie & Thiengo, 2003: 61.

TYPE LOCALITY.— Panama, Pearl Islands: Saboga Island (Morrison, 1952: 105).

DISTRIBUTION RECORDS — PANAMA: known only from the type locality. Morrison (1946) records this species from Pacheco Island, but later (1952) he discounted this locality.

Pomacea cumingi sanjoseensis Morrison, 1946

Pomacea cumingii sanjoseensis Morrison, 1946; Smithson. Misc. Coll., 106: 6-7; pl. 1, fig. 1 — Cowie & Thiengo, 2003, Malacologia, 45: 74.

TYPE LOCALITY.— Three small streams at the west end of San Jose Island, Pearly Islands, Panama. Holotype USNM 542136.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Pomacea dacostae Sowerby, (1909)

Ampullaria dacostae G. B. Sowerby, 1909; Proc. Malac. Soc. London, 8: 348 (name), 359 (description, fig.)

Pomacea dacostae (G. B. Sowerby). Cowie & Thiengo, 2003; Malacologia, 45: 61.

TYPE LOCALITY — Costa Rica. Syntype BMNH 10.19.35.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Pomacea flagellata flagellata (Say, 1827)

Ampullaria flagellata Say, 1827: 22 — Strebel, 1873: 25; pl. 3, fig. 14, pl. 3a, figs. 14 A-K, 15 — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 325 — Von Martens, 1899: 405; pl. 23, figs. 1, 4, 4a, 4b — Alderson, 1925: 35, 38, 42; pl. 9, fig. 7, pl. 10, figs. 2, 4 — H. B. Baker, 1922; Occ. Pap. Mus. Zool. Univ. Mich., (106): 37.

Pomacea flagellata (Say, 1827). Pain, 1964; Jour. of Conch., 25: 226-228; pl. 13, fig. 3 — Ruiz, 1987; Anales Inst. Biol. Univ. Nac. Auton. Mexico, 58: 21-34; pl. 1 (shell, operculum); pl. 2 (radula); pls. 3-6 (anatomy) — Cowie & Thiengo, 2003; Malacologia, 45: 64.

Pain, 1964, and Cowie & Thiengo, 2003 list the following names as synonyms.

Ampullaria violacea Valenciennes, 1833. (type locality not given)

Ampullaria ochracea Jay, 1836.

Ampullaria malleata Jonas, 1844. (type locality: Tabasco)

Ampullaria labiosa (Koch) Philippi, 1851.

Ampullaria lamarckii Philippi, 1851.

Ampullaria retusa (Olfers) Philippi, 1851.

Ampullaria phaeostoma Philippi, 1851.

Ampullaria reflexa var. melanostoma Philippi, 1862. (type locality: Papantla, and in freshwater lagoon between Amatlan and Cosamaloapan, Veracruz).

Ampullaria venetus Reeve, 1856.

Ampullaria hondurasensis Reeve, 1856.

Ampullaria flatalis Reeve, 1856. (type locality: Tabasco)

Ampullaria fumata Reeve, 1856.

Ampullaria columbiensis (Sowerby) Reeve, 1856.

AmpullariaVon Martensiana Neville, 1884.

Ampullaria strebeli Fischer & Crosse, 1890. (type locality: Misantla, Veacruz, in a small stream called the Brazo Seco)

Ampullaria strebeli var. prasina Fischer & Crosse, 1890.

Ampullaria belizensis Fischer & Crosse, 1890 [recognized as a distinct species here].

Ampullaria flagellata var. esculpta Fischer & Crosse, 1890. (type locality not given).

Ampullaria malleata var. arata Fischer & Crosse, 1890. (type locality: not given).

Ampullaria occlusa Fischer & Crosse, 1890. (type locality: freshwater lagoon of Tanesco, on the Pacific coast, three leagues from the mouth of the Rio Guacalata).

Ampullaria monachus Fischer & Crosse, 1890. (type locality: Santa Efigenia, Isthmus of Tehuantapec).

Ampullaria yucatanensis Fischer & Crosse, 1890.

Ampullaria eumicra Fischer & Crosse, 1890. (type locality: State of Oaxaca)

Ampullaria lemniscata Fischer & Crosse, 1890.

Ampullaria innexa Fischer & Crosse, 1890. (type locality: Monte de Mistam, near Coapam, Oaxaca).

Ampullaria malleata var. prasina Fisher & Crosse, 1890.

Ampullaria malleata var. oajacensis Fischer & Crosse, 1890. (type locality: Monte de Mistam, near Coapam, Oaxaca).

Ampullaria yucatanensis var. izabelensis Von Martens, 1899.

TYPE LOCALITY — For Ampullria flagellata only. A short distance below [Ciudad] Veracruz, Mexico. Lectotype ANSP 50645 (Pilsbry, 1991a: 325-326; H. B. Baker, 1964: 168).

DISTRIBUTION RECORDS — From Tamaulipas south along eastern Mexico to Dept. Petén, Guatemala and Belize, and along the Pacific coast from Colima southeast to Chiapas. Cowie & Thiengo (2003: 64) fide Pain, 1964 state that this species is distributed from central Mexico to the Rio Magdalena Basin, Colombia. Some records are as follow. COSTA RICA, Guanacaste Prov.: Rio de Cañas north of Santa Cruz (Pilsbry, 1920: 9). GUATEMALA, Dept. Petén: Tikal National Park (Basch, 1959; Occ. Pap. Mus. Zool. Univ. Mich., (612): 8) MEXICO. CAMPECHE: 5-11 mi. E of Campeche (Branson & McCoy, 1965). TABASCO: Villa Hermosa (Thompson, 1967). VERACRUZ: Los Tuxtlas, Laguna Escondida, Laguna Zacatál and Laguna Sontecomapán (Ruiz, 1987).

Widely introduced in the Pacific Islands and southeast Asia.

TAXONOMY — The systematic status of the many names associated with this widely distributed species is unsatisfactory. All of the names are based on shell characters that are variable and unreliable. However, to treat them as synonyms without careful morphological study or genetic analysis is as arbitrary as was their original descriptions. Very few locality citations from the literature are repeated here, because of the long lists of synonyms that may or may not apply to Pomacea flagellata and its subspecies. The reader is referred to Cowie & Thiengo (2003) for these locality citations.

Pomacea flagellata dysoni (Hanley, 1854)

Ampullaria dysoni Hanley, 1854; Conch. Misc.: pl. 2, fig. 1 — Reeve, 1856: pl. 11, fig. 49 — Von Martens, 1899: 417 — Kobelt, 1912; Martini & Chemnitz, Syst. Conch. Cab., Ampullaria: 110; pl. 44, fig. 1 — Alderson, 1925: 43; pl. 10, fig. 3.

Pomacea flagellata dysoni (Hanley). Pain, 1964; Jour. of Conch., 25: 230; pl. 13, fig. 2 — Cowie & Thiengo, 2003: 62.

TYPE LOCALITY — Honduras. Syntype BMNH 1907 11.21.65.

DISTRIBUTION RECORDS — HONDURAS: known only from the type locality.

Pomacea flagellata erogata (Fischer & Crosse, 1890)

Ampullaria erogata Crosse & Fischer, 1890; Jour. de Conchyl., 38: 251; pl. 46; figs. 6, 6a, 7 — Von Martens, 1899: 422 — Kobelt, 1912, in Martini & Chemnitz, Syst. Conch. Cab., Ampullaria: 134; pl. 50, figs. 9, 10.

Pomacea flagellata erogata (Crosse & Fischer). H. B. Baker, 1922; Occ. Pap. Mus. Zool. Univ. Mich., (106): 38 — Pain, 1964; Jour. of Conch., 25: 229-230; pl. 14, fig. 4 — Cowie & Thiengo, 2003: 63.

TYPE LOCALITY — Not given.

DISTRIBUTION — Same as for Pomacea f. flagellata (Pain, 1964).

Pomacea flagellata guatemalensis (Von Martens, 1899)

Ampullaria flagellata var. guatemalensis Von Martens, 1899: 413; pl. 22, figs. 11, 11a.

Pomacea flagellata flagellata (Say). Cowie & Thiengo, 2003; Malacologia, 45: 65.

TYPE LOCALITY — Paso Antonio, in the lower part of the Rio Michatoya, near the Pacific, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Pomacea flagellata livescens (Reeve, 1856)

Ampullaria livescens Reeve, 1856: pl. 5, fig. 21 — Alderson, 1925: 39; pl. 9, figs. 9, 10.

Ampullaria paludos livescens Reeve. Kobelt, 1912; in Martini & Chemnitz, Syst. Conch. Cab., Ampullaria: 118; pl. 46, fig. 1.

Pomacea flagellata livescens (Reeve). Pain, 1964; Jour. of Conch., 25: 228-229; pl. 13, fig. 1 — Cowie & Thiengo, 2003: 67.

Ampullaria ghiesbreghtii Reeve, 1856; pl. 26, fig. 123. — Strebel, 1873: 31, pl. 3, fig. 16.

Ampullaria ghiesbreghti Reeve — Fischer & Crosse, 1890: 233; pl. 47, fig. 8. — Alderson, 1925: 44; pl. 10, fig. 5 — Kobelt, 1912: 143; pl. 53, figs. 1-3.

Pomacea ghiesbreghti (Reeve). Pain, 1953; Proc. Malac. Soc. London, 29: 222.

Pomacea flagellata gheisbreghti (Reeve). Bequaert, 1957: 210.

Pomus giganteus Tristram, 1864: 414 (type locality: Lago de Petén, Guatemala).

Ampullaria chiapasensis Crosse & Fischer, 1890; Jour. de Conchyl., 38: 235. (type locality: Las Playas, Chiapas, in marshes).

Ampullaria flagellata giganteus (Tristram). Von Martens, 1899: 412; pl. 23, fig. 6.

Ampullaria tristrami Crosse & Fischer, 1890; Jour. de Conchyl., 38: 234. (type locality Lago de Petén, Guatemala).

Ampullaria flagellata var. tristami Von Martens, 1899: 413; pl. 22, figs. 1, 12 — Kobelt, 1912: 128; pl. 47, fig. 2 — Hinkley, 1920; Nautilus, 34: 45, 47, 49.

TYPE LOCALITY — For Ampullaria livescens only. Lake Petén, Dept. Petén, Guatemala. Syntype BMNH 1986214.

DISTRIBUTION RECORDS — Chiapas, Tabasco, and the Dept. Petén, Guatemala (Pain, 1964). BELIZE: (FLMNH collections). TABASCO: Rio Grijalva, 4 mi. S of Villlahermosa; Rio Grijalva 14 mi. N of Teapa (Thompson, 1957). GUATEMALA, Dept. Izabal: Plantera, Rio Dulces near Livingston; Jocola, north side of Lago de Izabal. Dept. Alta Verapaz: Panzos, Rio Polochic (Hinkley, 1920).

Pomacea lattrei lattrei (Reeve, 1856)

Ampullaria lattrei Reeve, 1856; Conchologica Iconographia, 10 (Ampullaria): pl. 5, fig. 22 — Tristram, 1863; Proc. Zool. Soc. (London): 414 — Kobelt, 1915: 146; pl. 54, figs. 1-4.

Ampullaria delattrei Reeve. Fischer and Crosse, 1890: 246 (emend.); pl. 45, figs. 4, 4a (shell) — Von Martens, 1899: 419; pl. 24, fig. 8. — Alderson, 1925: 31-32; pl. 9, fig. 8.

Ampullaria flagellata lattrei Reeve. Hinkley, 1920; Nautilus, 34:47.

Pomacea lattrei (Reeve), Cowie & Thiengo, 2003: 67.

TYPE LOCALITY. Cobán, Guatemala. Lectotype BMNH 2020665 (Cowie & Thiengo, 2003).

DISTRIBUTION RECORDS — Northern and eastern Guatemala. Hinkley (1920) lists this species from Rocks near Castillo San Filipe, Lago de Izabal, [Dept. Izabal], Guatemala.

REMARKS — The species was named by Reeve as Ampullaria lattrei for the French naturalist M. A. Delattre, because Reeve took the discoverer’s name to be de Lattre, a titular designation of nobility. The ICZN code Appendix D, para. 21 (d) prohibits the use of a particle denoting nobility in a scientific name. Fischer and Crosse emended the name to delattrei, conforming to its correct orthography. However, ICZN Article 32 requires that the original spelling must be maintained, except as provided by para. 32 (c) (ii). If a name is mis-spelled due to a typographic error or a lapsus calami, and this is clear in the publication without reference to other sources, then the name can be emended. Reeve’s original name must be retained, regardless of its incorrect etymology.

Pomacea lattrei chamana (Hinkley, 1920)

Ampullaria lattrei chamana Hinkley, 1920; Nautilus, 34: 53-54.

Pomacea lattrei chamana (Hinkley). Cowie & Thiengo, 2003: 59.

TYPE LOCALITY — Chama, near the Rio Tsalbha, Dept. Alta Verapaz, Guatemala. Lectotype ANSP 46321 (H. B. Baker, 1964: 168).

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Pomacea miltocheila (Reeve, 1856)

Ampullarius miltocheilus Reeve, 1856. Conchologica Iconica, 10: pl. 25, figs. 120a-b — Von Martens, 1899: 418 — Pain, 1953; Proc. Malac. Soc. London, 29: 122-123.

Ampullaria miltochilus Reeve. Fischer & Crosse, 1890: 247.

Pomacea cumings (King & Broderip, 1831). Cowie & Thiengo, 2003; Malacologia, 45: 69.

TYPE LOCALITY.— Province of Chiapes [= Chiapas], Mexico. Lectotype BMNH 20020668.

DISTRIBUTION RECORDS.— VERACRUZ: Cazcajal, on the upper part of the Rio Uzpanapa (Pain, 1953)

REMARKS — Cowie & Thiengo give no justification for synonymizing this species with Pomacea cumingi (King & Broderip, 1831), a species from Panama.

Pomacea pealiana (Lea, 1834)

Ampullaria pealiana Lea, 1834; Obs. Unionidae II: 16, tb. 23, fig. 77.

Ampullaria pealeana Lea. Von Martens, 1899: 423; pl. 24, figs. 12, 13.

Pomacea pealiana (Lea). Cowie & Thiengo, 2003; Malacologia, 45: 71.

TYPE LOCALITY — Turbaco, Colombia. Holotype ANSP 192933 (Abbott, 1955).

DISTRIBUTION RECORDS — Colombia, Ecuador, Venezuela and Panama (Cowie & Thiengo, 2003: 71). PANAMA, Veraguas Prov.: Veraguas (Von Martens, 1899).

Pomacea picta (Reeve, 1856)

Ampullaria picta Reeve, 1856: pl. 24, figs. 117a, b.

Pomacea picta (Reeve). Cowie & Thiengo, 2003; Malacologia, 45: 72.

TYPE LOCALITY — Mazatlan. Here restricted to Mazatlán, Guerrero, which is on the road south from Mexico City to Acapulco. This is the locality from where many 19th Century species originated, very few of which occur at Mazatlán, Sinaloa. Syntypes BMNH 1907.11.21.91-92.

DISTRIBUTION RECORDS — GUERRERO: known only from the type locality.

Pomacea zeteki Morrison, 1946

Ampullaria cumingi King & Broderip. Von Martens, 1899: 422 (in part).

Pomacea zeteki Morrison, 1946; Smithson. Misc. Coll., 106: 8 — Cowie & Theingo, 2003; Malacologia, 45: 77.

TYPE LOCALITY.— A shallow margin of the Chagres River, near Gatuncilla, Panama. Holotype USNM 542137.

DISTRIBUTION RECORDS — PANAMA: recorded only from the type locality.


Superfamily VIVIPAROIDEA

Family VIVIPARIDAE Gray, 1847

A single species of Viviparidae of questionable status has been recorded from Mexico.

Subfamily VIVIPARINAE Gray, 1847

Genus Viviparus Montfort, 1810

Viviparus inornatus (Binney, 1865)

Vivipara inornata Binney, 1865; Amer. Jour. Conch., 1: 49; pl. 7, fig. 1 (shell) — Binney, 1865; Smith. Misc. Coll., (144): 113-114; text-fig. 225 (shell) — von Martens, 1899: 426.

Paludina inornata (Binney). Fischer & Crosse, 1891: 291.

Viviparus geogrianus (Lea). Clench & Fuller, 1965; Occ. Pap. on Moll., 2: 398-399; pl. 64, fig. 6 (lectotype).

TYPE LOCALITY — Chopatilo. von Martens (1899) suggests that the orthography of Chopatilo probably is incorrect. He gives three localities with different spellings that may have been the place of origin of the types, one in Michoacán, one in Sonora and one in Nuevo León. The latter locality is here selected as the most probable: Hacienda Chapotito, near Cerralvo, Nuevo León (26.10º N, 99.62º W). Lectotype MCZ 234704 (Clench & Fuller, 1965: 397).

DISTRIBUTION RECORDS — NUEVO LEÓN ?: known only from the type locality.

REMARKS — Clench & Fuller (1965: 398-399) suggest that Vivipara inornata may be a synonym of Viviparus georgianus (Lea, 1834) because of its resemblance to atypically green and unbanded specimens from northern Florida. This synonymy seems unlikely because the weakly impressed suture that characterizes Viviparus inornatus differs strikingly from the much more deeply impressed suture of Viviparus georgianus.


Superfamily CYCLOPHOROIDEA

Family NEOCYCLOTIDAE Kobelt & Moellendorff, 1897

TYPE GENUS — Neocyclotus Fischer & Crosse, 1886.

DISTRIBUTION — American tropics, South Pacific islands.

TAXONOMY — Twenty-eight genera of Neocyclotidae are recognized currently in the neotropical region. Another six genera occur in the Pacific region. The generic and higher taxonomy of the cyclophorids is very unsettled. There is little agreement on the current classification regarding the numbers of families, subfamilies and genera. Three subfamilies of Neocyclotidae are recognized in the Neotropics. The Megalomastomatinae is found in Cuba, Hispaniola, Puerto Rico, and the Virgin Islands, and in eastern Mexico, Guatemala and Belize. The Crocidopomatinae is found in Cuba, Hispaniola and the Lesser Antilles (Thompson, 1967). The Neocyclotinae is found in the Greater and Lesser Antilles, and the mainland from Mexico south to Bolivia.

Subfamily MEGALOMASTOMATINAE Blanford, 1864

Megalomastominae Torre & Bartsch, 1942; Bull. U. S. Nat. Mus., 181: 2 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 142. Thompson, 1969; Zoologica, 54: 37.

TYPE GENUS — Megalomastoma Swainson, 1840.

DISTRIBUTION — Greater Antilles, Eastern Mexico, Guatemala and Belize.

TAXONOMY — Five genera are recognized. Two occur in the Mexico-Central American Region.

Genus Aperostoma Troschel, 1847

Aperostoma Troschel, 1847: 44 — Heremanssen, 1852: 10 — H. B. Baker, 1932; Nautilus, 35: 14 — H. B. Baker, 1943; Nautilus, 56: 137 — Morrison, 1955; Jour. Wash. Acad. Sci., 45: 152 — Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 46-48 — Thompson, 1969; Zoologica, 54: 37.

Cyrtotoma Mõrch, 1852; Catalogus conchyliorum, 1: 40 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 169.

Habropoma Crosse & Fischer, 1880: 8 — Fischer & Crosse, 1890: 127-129.

TYPE SPECIES — Aperostoma: Cyclostoma mexicanum Menke, 1830. Cyrtotoma: Cyclostoma mexicanum Menke, 1830 — Habropoma: Cyclostoma mexicanum Menke, 1830.

DISTRIBUTION — Eastern Mexico from eastern San Luís Potosí south to Oaxaca and Veracruz.

TAXONOMY — Three species and one subspecies are recognized currently. Bartsch & Morrison recognized eight, most of which Solem placed in synonymy.

Aperostoma mexicanum mexicanum (Menke, 1830

Cyclostoma mexicanum Menke, 1830; Symopsis method. mollusc.: 133.

Aperostoma mexicanum (Menke). Troschel, 1847; Zeitschr. Malak., 4: 44 — Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 48; pl. 5, figs. 5-6 (shell), 10; pl. 6, figs. 6-10 (shell).

Cyrtotoma mexicanum (Menke). Mõrch, 1852; Catalogus concyliorum, 1: 40 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 173; pl. 22, figs. 4-6 (shell).

Cyrtotoma mexicanum mexicanum (Menke). H. B. Baker, 1922; Occ. Pap. Mus. Zool. Univ. Mich., (106): 43-44.

Habropoma mexicanum (Menke). Fischer & Crosse, 1890: 130-132; pl. 35, figs. 5-5b (shell).

Cyclophorus mexicanus (Menke). Strebel, 1873: 8-9; pl. 1, fig. 1 (shell); pl. 1a, figs. 1-1b (shell) — Von Martens, 1890: 7-8.

Cyrtotoma avus Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 169-170; pl. 22, figs. 22-24 (shell).

Cyrtotoma ignotum Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 171; pl. 22, figs. 16-18 (shell).

Cyrtotoma fischeri Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 171-172; pl. 22, figs. 13-15 (shell).

TYPE LOCALITIES — Cyclostoma mexicanum: Papantla, Veracruz. Cyrtotoma avus: Motzorongo, Veracruz; holotype USNM 128285. Cyrtotoma ignotum: Mexico; holotype USNM 523515. Cyrtotoma fischeri: Hacienda Coaotolapam, Veracruz; holotype USNM 515789.

DISTRIBUTION RECORDS — OAXACA: Playa Vicente; Tustepe (Von Martens, 1890). PUEBLA: Multatoyuca (Bartsch & Morrison, 1942). VERACRUZ: Papantla; Misantla; Cuesta de Papantla; Jalapa; Cerro de Plumas (Von Martens, 1890); Coatotolapam; Cordoba; Atoyac; Sumidero; Cordoba, Oriaba; Antigua (Solem, 1956a).

TAXONOMY — The synonymy used here follows Solem, 1956a, when significantly less material was available in museum collections. The taxonomy of the genus needs to be reviewed. Until then the distribution records given above should be regarded as tentative.

Aperostoma mexicanum salleanum (Von Martens, 1865)

Cyclophorus salleanus Von Martens, 1865: 151.

Habropoma salleana (Martens). Fischer & Crosse, 1880: 133-134; pl. 35, figs. 4-4b (shell); pl. 38, figs. 1-1a (shell).

Cyclophorus (Cyrtotoma) salleanus Von Martens. Von Martens, 1890: 7.

Cyrtotoma salleanum (Von Martens). Kobelt & Möllendorff, 1907; Nach. Blätt. Deut. Ges., 29: 140 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 170-171; pl. 22, figs. 19-21 (shell).

Cyrtotoma mexicanum salleanum (Von Martens). H. B. Baker, 1922; Occ. Pap. Mus. Zool. Univ. Mich., (106): 42; pl. 16, figs. 8-12 (shell).

Aperostoma mexicanum salleanum (Von Martens). H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 51 — Thompson, 1969; Zoologica, 54: 37-39; text-fig. 2c (female reproductive system).

Aperostoma mexicanum mexicanum (Menke) (in part). Solem, 1956a: 48-50.

TYPE LOCALITY — Cordova [Cordoba], Veracruz.

DISTRIBUTION RECORDS — VERACRUZ: Barranca de Santa Maria, near Mirador; Orizaba; Misantla; Quilate, nr. Misantla; Atoyac; Coatepec; Jalapa (Von Martens, 1890); 2.9 mi. E of Cordoba, 2500 ft. alt.; 4.3 mi. E of Cordoba, 2300 ft. alt.; 1.9 mi. SW, 0.8 mi. N of Fortín, 2900 ft. alt. (Thompson, 1969).

Aperstoma palmeri (Bartsch & Morrison, 1942)

Cyrtotoma palmeri Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 172-173; pl. 22, figs. 1-3 (shell).

Aperostoma mexicanum palmeri (Batsch & Morrison). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 50-51; pl. 5, figs. 1-4 (shell); pl. 6, figs. 1-5 (shell) — Correa-Sandoval, Gutierrez & Reza 1998; Acta Zol. Mex., n. s. (73): 13.

Aperostoma palmeri (Bartsch & Morrison). Thompson, 1969; Zoologica, 54: 39; text-figs. 1-1B (pallial organs).

TYPE LOCALITY — Gomez Farías, Tamaulipas. Holotype USNM 198079.

DISTRIBUTION RECORDS — HIDALGO: Chapulhuacan (Solem, 1956a). SAN LUÍS POTOSÍ: 11.4 mi. E of Xilitla, 1100 ft. alt.; 7.5 mi. E of Xilitla (Thompson, 1969); 6 km SE of Xilitla, 830 m alt. (21°23’10” N, 99°03’56” W) (Correa-Sandoval, et al, 1998). TAMAULIPAS: Gomez Farias.

Aperostoma walkeri H. B. Baker, 1928

Aperostoma walkeri H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich.; (193): 51; pl. 6, figs. 38, 40 (shell); pl. 6, fig. 39 (operculum) — Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 51-52; pl. 5, figs. 14-15 — Correa-Sandoval, 2000; Acta Zool. Mex., n. s. (79): 8.

Cyrtotoma walkeri (H. B. Baker). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 174; pl. 22, figs. 10-12.

Cyrtotoma goldmani Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 174; pl. 22, figs. 7-9.

TYPE LOCALITIES — Aperostoma walkeri: forests on south side of Vaso de Tenango, Nacaxa, Puebla; holotype in the UMMZ. Cyrtotoma goldmani: Multatoyuca [Metlaltoyuca], Puebla; holotype USNM 53516.

DISTRIBUTION RECORDS — PUEBLA: Metlaltoyuca; Necaxa. VERACRUZ: Coyutla; Misantla (Solem, 1956a); El Cedral, carr. Poza Rica-Tajín (20°29’11” N, 97°25’23” W); Ruinas El Tajín (20°26’29” N, 97°22’30” W) (Correa-Sandoval, 2000).

Genus Tomocyclus Crosse & Fischer, 1872

Tomocyclus Crosse & Fischer, 1872; Jour. de Conchyl., 20: 76 — Fischer & Crosse, 1888: 113-11 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 142-143 — Thompson, 1963; Breviora, (181): 1.

TYPE SPECIES — Tomocyclus gealei Crosse & Fischer, 1872.

DISTRIBUTION — Belize, eastern Guatemala and southeast Mexico in the states of Chiapas and Veracruz.

TAXONOMY — Five species are recognized.

Tomocyclus gealei Crosse & Fischer, 1872

Tomocyclus gealei Crosse & Fischer, 1872: 77 — Fischer & Crosse, 1886: 118-120; pl. 40, figs. 1-3 (shell) — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 143-144; pl. 19, fig. 1 (shell) — Thompson, 1963: 2-3.

Megalomastoma (Tomocyclus) gealei (Crosse & Fischer). Von Martens, 1890: 10.

TYPE LOCALITY — Chiapas.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Baja Verapaz: woods between Tactic and Tamahu; Polochic Valley above Panzos and Senahu (Von Martens, 1890).

Tomocyclus fistularus Thompson, 1963

Tomocyclus fistularus Thompson, 1963; Breviora, (181): 3-4; pl. 1, figs. 1-3 (shell).

TYPE LOCALITY — High rainforest at Valentine Camp, 50 mi. southwest of Cayo, British Honduras [Belize]. Holotype UMMZ 194095.

DISTRIBUTION RECORDS — BELIZE – GUATEMALA. The type locality, if correct, would place the species in the Dept. Petén, Guatemala.

Tomocyclus guatemalensis Pfeiffer, 1851

Cyclostoma guatemalensis Pfeiffer, 1851: 245 — Pfeiffer, 1853: 267; pl. 36, figs. 1-14 (shell).

Tomocyclus guatemalensis (Pfeiffer). Crosse & Fischer, 1872: 76 — Fischer & Crosse, 1886: 124; pl. 40, fig. 11 (shell) — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 144; pl. 19, fig. 11 (shell) — Thompson, 1963; Breviora, (181): 8

TYPE LOCALITY — Vera Paz, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Tomocyclus lunai Bartsch, 1945

Tomocyclus guatemalensis (in part) Fischer & Crosse, 1886: 124; pl. 40, fig. 11a (shell).

TOmocyclus lunai Bartsch, 1945; Proc. Biol. Soc. Wash., 58: 63-63 — Thompson, 1963; Breviora, (181): 8.

TYPE LOCALITY — Santecomopan, Veracruz. Holotype USNM 573547.

DISTRIBUTION RECORDS — VERACRUZ: Santecomopan; San Martin Tuxtla; south slope of Volcán San Martin, 1040 ft. alt.; Volcán San Martin (Thompson, 1963).

Tomocyclus simulacrum (Morelet, 1849)

Cyclostoma simulacrum Morelet, 1849; Test Noviss., I: 22.

Cyslostoma copanense Sowerby, 1850; Thesaurus Conchyl., 1 (suppl.): 165; pl. 31B, figs. 310, 311 (shell).

Tomocyclus simulacrum (Morelet). Crosse & Fischer, 1872; Jour. de Conchyl., 20: 76 — Fischer & Crosse, 1886: 121-124; pl. 40, figs. 9, 9a (shell); pl. 44, figs. 1, 1a (shell) — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 146-147; pl. 19, fig. 6 (shell) — Thompson, 1963; Breviora, (181): 5-8.

Megalomastoma simulacrum var. gracilius Von Martens, 1890: 10.

Tomocyclus siphonis Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 145; pl. 19, fig. 5 (shell).

Tomocyclus constrictus Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 145-146; pl. 19, fig. 2 (shell).

TYPE LOCALITIES — Cyclostoma simulacrum: Dept. Petén, Guatemala. Cyclostoma copanensis: Coban, Guatemala (?). Megalomastoma simulacrum var. gracilius: Between Tactic and Tamahu, Dept. Baja Verapaz, Guatemala. Tomocyclus siphonis: Alta Vera Paz, Guatemala. Tomocyclus constrictus: Coban, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA. Dept. Alta Verapaz: Coban; Chama; Finca de Providensia; nr. Arroyo Yalchatila, 4 km SW of Seiba; 1 km N of Finca Samac; 55 km NE of Coban; Chinaja (Thompson, 1963). Dept. Quiche: 4-6 km NW of Hacienda Pacala (Thompson, 1963).

Subfamily NEOCYCLOTINAE Kobelt & Möllendorff, 1897

DISTRIBUTION — Widely distributed throughout the neotropical realm.

TAXONOMY — About 25 genera and numerous subgenera are recognized. Thirty-seven species occur in the study area.

Genus Neocyclotus Fischer & Crosse, 1886

Neocyclotus Fischer & Crosse, 1886: 148 — Morrison, 1955; Jour. Wash. Acad. Sci., 45: 156 — Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 52-53 — Thompson, 1969; Zoologica, 54: 65-66.

Aperostoma (Neocyclotus) Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 203.

Austrocyclotus Bartsch, 1942: 132 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 195-196 — Morrison, 1955; Jour. Wash. Acad. Sci., 45: 156.

TYPE SPECIES — Neocyclotus: Cyclostoma dysoni Pfeiffer, 1851 (by subsequent designation; Pilsbry, 1910: 533). Austrocyclotus: Cyclostoma stramineum Reeve, 1843 (by original designation).

DISTRIBUTION — Veracruz south to Ecuador, Venezuela and the Lesser Antilles.

TAXONOMY — About 25 species are recognized. Six occur in the study area. Neocyclotus dysoni is widely distributed from Panama north to Veracruz. Bartsch & Morrison (1842) divided the species into 13 subspecies. These are listed below, although the validity of some are in doubt (Solem, 1956). Many earlier distribution records are omitted from this report for Neocyclotus dysoni because their identities are nearly impossible to reconcile within the present classification.

Neocyclotus bisinuatus (Von Martens, 1864)

Cyclotus bisinuatus Von Martens, 1864; Malak. Blätt., 11: 113; pl. 3, figs. 1-2 (shell).

Cyclotus (Aperostoma) bisinuatus (Von Martens). Von Martens, 1890: 3.

Neocyclotus (Neocyclotus) bisinuatusm (Von Martens). Kobelt & Möllendorff, 1897; Nachrb. Deut. Malak. Ges., 29: 137.

Aperostoma (Aperostoma) bisinuatum (Martens). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 235; pl. 33, figs. 5, 6 (shell).

Neocyclotus bisinuatus (Von Martens). Thompson, 1969; Zoologica, 54: 71-73; pl. 1, fig. K (operculum); text-fig. 12, A-B (male reproductive system); text-fig. 14, A (female reproductive system).

TYPE LOCALITY — Elevated plains of Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA: Cartago Prov.: Tapantí, 4300 ft. alt.; 5 mi. E of Villa Neily; Inter American Agricultural Institute, Turrialba, 2000 ft. alt. (Thompson, 1969). GUATEMALA, Dept. Retalhuleu: Costa Cuco above Retalhuleu; San Francisco Miramar, 2500 ft. alt. Dept. Huehuetenango: on the slope of Volcán de Santa Maria, 3000-5000 ft. alt. (Von Martens, 1890).

Neocyclotus capscelius Thompson, 1969

Neocyclotus capscelius Thompson, 1969; Zoologica, 54: 73; pl. V, figs. e-h (shell, operculum).

TYPE LOCALITY — A wooded ravine on Cerro de la Muerte, 10.5 km N of San Isidro El General, San Jose Prov., Costa Rica. Holotype FLMNH 20148.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Neocyclotus chrysacme (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) chrysacme Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 219; pl. 20, figs. 13-15 (shell).

TYPE LOCALITY — Wani, Nicaragua. Holotype USNM 186112.

DISTRIBUTION RECORDS — NICARAGUA: known only from the type locality.

Neocyclotus dysoni dysoni (Pfeiffer, 1851)

Cyclostoma dysoni Pfeiffer, 1851; Proc. Zool. Soc. London: 243 — Pfeiffer, 1853; in Martini & Chemnitz Syst. Conch. Cab., 1: 259; pl. 35, figs. 5-6 (shell).

Neocyclotus dysoni (Pfeiffer) in part. Fischer & Crosse, 1888: 164.

Cyclotus (Aperostoma) dysoni (Pfeiffer) in part. Von Martens, 1890: 3.

Poteria (Neocyclotus) dysoni (Pfeiffer). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137): 33.

Aperostoma (Neocyclotus) dysoni dysoni (Pfeiffer). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 207-208; pl. 28, figs. 28-30 — Thompson, 1969; Zoologica, 54: 67-68.

TYPE LOCALITY — Honduras.

DISTRIBUTION RECORDS — HONDURAS, Dept. Comayagua: 4 km SSW of Comayagua; 15.1 km N of Comayagua (Thompson, 1969).

Neocyclotus dysoni affinis (Von Martens, 1890)

Cyclotus (Aperostoma) dysoni affinis Von Martens, 1890: 4; pl. 1, fig. 1 (shell).

Neocyclotus (Neocyclotus) dysoni affinis (Von Martens). Kobelt & Möllendorff, 1897; Nachrb. Deut. Malak. Ges., 29: 137.

Poteria (Neocyclotus) dysoni affinis (Von Martens). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137): 34.

Aperostoma (Neocyclotus) dysoni affine (Von Martens). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 210-211; pl. 28, figs. 22-24 (shell).

TYPE LOCALITY — Bugaba, Panama.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Neocyclotus dysoni ambiguus (Von Martens, 1890)

Cyclotus (Aperostoma) dysoni ambiguus Von Martens, 1890: 4.

Neocyclotus (Neocyclotus) dysoni ambiguus (Von Martens). Kobelt & Möllendorff, 1897; Nachrb. Deut. Malak. Ges., 29: 137.

Poteria (Neocyclotus) dysoni ambiguus (Von Martens, 1890). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137): 34.

Aperostoma (Neocyclotus) dysoni ambiguum (Von Martens). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 211; pl. 28, figs. 10-12 (shell).

Neocyclotus dysoni ambiguum (Von Martens). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 53 — Thompson, 1969; Zoologica, 54: 66; text-fig. 11, C-D (male reproductive system); text-fig. 13, A (female reproductive system).

TYPE LOCALITY — Soledad, between Cordoba and Orizaba, Veracruz.

DISTRIBUTION RECORD — CHIAPAS: Ixtapa; Tecpatán (Solem, 1956); 8.0 mi. N of Tuxtla Gutierrez, 3100 ft. alt.; 8.6 mi. E of Chiapa de Corze, 3100 ft alt.; 14.9 mi. E of Chiapa de Corzo, 4400 ft. alt. (Thompson, 1969). OAXACA: Rio Grande (Solem, 1956). TABASCO: 2.4 mi. E of Teapa; 2.6 mi. E of Teapa; 4.0 mi. W of Teapa (Thompson, 1969). VERACRUZ: Jalapa; Octopan (Bartsch & Morrison, 1942); Laguna Encontada, nr. San Andres Tuxtla (Thompson, 1969).

Neocyclotus dysoni aureus (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) dysoni aureus Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 209; pl. 28, figs. 13-15 (shell).

Neocyclotus dysoni aureum (Bartsch & Morrison). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 53-54 — Branson & McCoy, 1963; Nautilus, 76: 103.

TYPE LOCALITY — Panistlahuaca, Oaxaca. Holotype USNM 523970.

DISTRIBUTION RECORDS — CAMPECHE: 5-11 mi. E of Campeche (Branson & McCoy, 1963). OAXACA: Gamboa; Panistlahuaca (Solem, 1956). EL SALVADOR: Lago de Coatepeque. GUATEMALA: Lago de Amatitlan (Solem, 1956).

Neocyclotus dysoni berendti (Pfeiffer, 1861)

Cyclotus berendti Pfeiffer, 1861; Malak. Blätt., 8: 171.

Neocyclotus berendti (Pfeiffer). Fischer & Crosse, 1886: pl. 28, figs. 4-5 (shell) — Fischer & Crosse, 1888: 167 — Branson & McCoy, 1963; Nautilus, 76: 103.

Cyclotus (Aperotoma) dysoni berendti (Pfeiffer). Von Martens, 1890: 5.

Cyclotus dysoni form multilineatus Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 325.

Poteria (Neocyclotus) berendti (Pfeiffer). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137) 33. Bequaert & Clench, 1933; Pub. Carnegie Inst. Wash., (431): 350.

Aperostoma (Neocyclotus) dysoni berendti (Pfeiffer). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 212; pl. 29, figs. 4-6 (shell).

Aperostoma dysoni berendti (Pfeiffer). Harry, 1950; Occ. Pap. Mus. Zool. Univ. Mich., (524): 25-26.

Neocyclotus dysoni berendti (Pfeiffer). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 53 — Rehder, 1966; Proc. Biol. Soc. Wash., 79: 278 — Thompson, 1967; Bull. Fl. St. Mus., 11: 228.

TYPE LOCALITY — Dead shells found on the shore, Veracruz, Veracruz (Von Martens doubts this locality).

DISTRIBUTION RECORDS — CAMPECHE: 5.1 mi. NNW of Dzibalchén (Thompson, 1967). QUINTANA ROO: 12 km from Icaiche (Rehder, 1966; 7.1 mi. NNW of Xiatil; 4.0 mi. E of Xpujil (Thompson, 1967). YUCATAN: 8 mi. S of Progreso; near Chichen Itza (Harry, 1950); Chichen Itza (Bequaert & Clench, 1933); 0.5 mi. E of Becanchén; 10.0 mi. SE of Becanchén (Thompson, 1967); 1.5 mi. S off Libre Union (Branson & McCoy, 1963).

Neocyclotus dysoni cookei (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) dysoni cookei Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 215-216; pl. 29, figs. 10-12 (shell).

Neocyclotus dysoni cookei (Bartsch & Morrison, 1942). Basch, 1959; Occ. Pap. Mus. Zool. Univ. Mich., (612): 6 — Rehder, 1966; Proc. Biol. Soc. Wash., 79: 278 — Thompson, 1967; Bull. Fla. St. Mus., 11: 228.

TYPE LOCALITY — Uaxactun, Dept, Petén, Guatemala. Holotype USNM 524006.

DISTRIBUTION RECORDS — BELIZE: nr. Punta Gorda; foot of a limestone hill, left bank of the Belize River, 1.5 mi. S of Cayo; W of Gales Point (Bartsch & Morrison, 1942). GUATEMALA, Dept. Petén: Magalango; 2 km S of Flores; 2 km S of Puebla Nueva (Bartsch & Morrison, 1942); Tikal National Park (Basch, 1959). CAMPECHE: 7.2 mi. S of Pixtun; 19.2 mi. E of Silvituc; 10.2 mi. E of Escarcega (Thompson, 1967). QUINTANA ROO: 12 km from Icaiche (Rehder, 1966).

Neocyclotus dysoni dyeri (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) dysoni dyeri Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 205; pl. 28, figs. 31-33 (shell).

Neocyclotus dysoni dyeri (Bartsch & Morrison). Thompson, 1969; Zoologica, 54: 68.

TYPE LOCALITY — La Ceiba, Honduras. Holotype USNM 215592.

DISTRIBUTION RECORDS — HONDURAS, Dept. Colon: Belfate (Thompson, 1969).

Neocyclotus dysoni hinkleyi (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) dysoni hinkleyi Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 206-207; pl. 28, figs. 19-21 (shell).

TYPE LOCALITY — Guatemala. Holotype USNM 523968.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: Cacao Finca, Tres Aguas, nr. Senahu; Chama; Secanquim, 500 m alt. Dept. Izabal: Maya Farms, Quiriqua (Bartsch & Morrison).

Neocyclotus dysoni nicaraguensis (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) dysoni nicaraguensis Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 214-215; pl. 29, figs. 16-18 (shell).

Neocyclotus dysoni nicaraguense (Bartsch & Morrison). Thompson, 1969; Zoologica, 54: 68 — Pérez & López, 2002: 50-52.

TYPE LOCALITY — Polvón, Nicaragua. Holotype USNM 524005.

DISTRIBUTION RECORDS — COSTA RICA, Prov. Guanacaste: 3.8 mi. S of Nicoya; 2.2 mi. SE of Nicoya, 500 ft. alt.; 1.2 mi. E of Caimital (Thompson, 1969). NICARAGUA, Dept. Grenada Dirio [Diria ?] (Bartsch & Morrison, 1942). Numerous localities in the Dept. Estelí, Dept. Matagalpa, Dept. Managua, Dept. Leon (Peréz & López, 2002).

Neocyclotus dysoni ruatanensus (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) dysoni ruatanensus Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 207; pl. 28, figs. 7-9 (shell).

Neocyclotus dysoni var. ruatanensus (Bartsch & Morrison). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 54.

TYPE LOCALITY — Ruatan [Roatán] Island, Honduras. Holotype USNM 364702.

DISTRIBUTION RECORDS — HONDURAS: known only from the type locality.

Neocyclotus dysoni sallei (Bartsch & Morrison, 1942)

Cyclotus (Aperostoma) dysoni var. minor Von Martens, 1890: pl. 1, fig. 2 (shell) (not Cyclotus corrugatior minor Chitty, 1857).

Poteria (Neocyclotus) dysoni minor (Von Martens). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137) 33.

Aperostoma (Neocyclotus) dysoni sallei Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 213; pl. 29, figs. 7-9 (shell).

Neocyclotus dysoni sallei (Bartsch & Morrison, 1942). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 53.

TYPE LOCALITY — Yucatan.

DISTRIBUTION RECORDS — YUCATAN: known only from the type locality.

Neocyclotus dysoni sumichrasti (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) dysoni sumichrasti Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 209-210; pl. 28, figs. 25-27 (shell).

TYPE LOCALITY — Chontales forest, Nicaragua. Holotype USNM 523674.

DISTRIBUTION RECORDS — NICARAGUA: known only from the type locality.

Neocyclotus dysoni valerioi (Bartsch & Morrison, 1942)

Aperostoma (Neocyclotus) dysoni valerioi Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 213-214; pl. 29, figs. 19-21 (shell).

TYPE LOCALITY — Cervantes, [Prov. Cartago], Costa Rica. Holotype USNM 524003.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Neocyclotus panamensis Da Costa, 1904

Neocyclotus panamensis Da Costa, 1904; Proc. Malac. Soc. London, 6: 6; pl. 1, figs. 6-9 (shell).

Poteria (Neocyclotus) panamensis (Da Costa). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137) 37.

Aperostoma (Austrocyclotus) panamense (Da Costa). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 197-198; pl. 27, figs. 3-5.

TYPE LOCALITY — Chiriqui, Panama.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Neocyclotus simplicostus Thompson, 1969

Neocyclotus simplicostus Thompson, 1969; Zoologica, 54: 68-71; pl. 11, figs. J-L (shell); pl. 1, fig. J (operculum); text-fig. 12, E (male reproductive system) text-fig. 13, D (female reproductive system).

TYPE LOCALITY — A ravine 4.2 mi. northwest of Escuintla, Chiapas; 300 ft. alt. Holotype FLMNH 20167.

DISTRIBUTION RECORDS — CHIAPAS: 21.3 mi. NW of Huixtla, 300 ft. alt.; 32.5 mi. NW of Huixtla, 200 ft. alt. (Thompson, 1969).

Genus Incidostoma Bartsch & Morrison, 1942

Aperostoma (Incidostoma) Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 187.

Incidostoma Morrison, 1955; Jour. Wash. Acad. Sci., 45: 155.

Neocyclotus (Incidostoma), Thompson, 1969; Zoologica, 54:73-74.

TYPE SPECIES — Aperostoma (Incidostoma) malleatum Bartsch & Morrison, 1942.

DISTRIBUTION — Costa Rica south to Bolivia and Brazil.

TAXONOMY — Aperostoma Troschel was used by Bartsch & Morrison (1942: 187-284) for a large group of mainland species. The genus name is not available for this group because Herrmannsen (1852) designated Cyclostoma mexicanum as the type species, which belongs in a different subfamily, the Megalomastomatinae. Of the eight subgenera of Aperostoma recognized by Bartsch (1942), by Bartsch & Morrison (1942) and by Morrison (1955), Neocyclotus is the oldest available name, and Incidostoma is the next oldest available name. Incidostoma and Neocyclotus differ sFLMNHficiently to be regarded as separate genera, following Morrison (1955).

Bartsch (1942), and Bartsch & Morrison (1942) list 72 species in Aperostoma (= Incidostoma as used here). Ten species occur in the study area.

Incidostoma brujense (Bartsch & Morrison, 1942)

Aperostoma (Aperostoma) brujense Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 244; pl. 34, figs. 13-15.

TYPE LOCALITY — Cerro Bruja, Panama; 500 ft. alt. Holotype USNM 251418.

DISTRIBUTION RECORDS — PANAMA: mountains around Gaspasalana, High Mamoni (Bartsch & Morrison, 1942).

Incidostoma carmioli (Bartsch & Morrison, 1942)

Aperostoma (Incidostoma) carmioli Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 233; pl. 32, figs. 19-21.

Neocyclotus (Incidostoma) carmioli (Bartsch & Morrison). Thompson, 1969; Zoologica, 54: 74.

TYPE LOCALITY — Chitaria, Costa Rica. Holotype USNM 405227.

DISTRIBUTION RECORDS — COSTA RICA, Cartago Prov.: Rio Chitaria, 2 km. N of Jabillas, 3000 ft. alt. (Thompson, 1969).

Incidostoma confusum (Sykes, 1901)

Cyclostoma giganteum Reeve. Pfeiffer, 1848; in Martini & Chemnitz Syst. Conch. Cab., 1: 11; pl. 1, fig. 11-14 (shell).

Aperostoma confusum Sykes, 1901; Jour. of Malac., 8: 106; pl. 10, fig. 2.

Poteria (Neocycolus) confusum (Sykes). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137) 42.

Aperostoma (Aperostoma) confusum (Sykes). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 237; pl. 33, figs. 1-3.

TYPE LOCALITY — Panama.

DISTRIBUTION RECORDS — COLOMBIA, Dept. Choco: Acandí, a small village in the Gulf of Atrato, on the boundary between Panama and Colombia (Bartsch & Morrison, 1942).

Incidostoma costaricense (Von Martens, 1876)

Cyclotus quitesis costaricensis Von Martens, 1876: 257.

Aperostoma (Incidosoma) costaricense (Von Martens). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 234; pl. 32, figs. 16-18 (shell).

TYPE LOCALITY — Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA (?): unknown.

Incidostoma exiguum (Bartsch & Morrison, 1942)

Aperostoma (Incidostoma) exiguum Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 234-235; pl. 32, figs. 10-12 (shell).

TYPE LOCALITY — Zorquin Valley, Talamanca, Costa Rica. Holotype USNM 190281.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Incidostoma gigantea (Reeve, 1842)

Cyclostoma giganteum Reeve, 1842; Conchologica systematica, 2: pl. 99, fig. 17 — Sowerby, 1843; Thesaurus conchyliorum: 92; pl. 23, figs. 8, 9 (shell).

Neocyclotus giganteus (Reeve). Kobelt & Möllendorff, 1897; Nachrb. Deut. Malak. Ges., 29: 137.

Aperostoma giganteum (Reeve). Sykes, 1901: 105; pl. 10, fig. 1 (shell).

Poteria (Neocyclotus) gigantea (Reeve). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137) 40, 42.

Aperostoma (Incidostoma) giganteum (Reeve). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 237-238; pl. 33, figs. 7-9 (shell).

Incidostoma gigantea (Reeve). Morrison, 1955; Jour. Wash. Acad. Sci., 45: 157.

TYPE LOCALITY — In woods near Panama, Panama.

DISTRIBUTION RECORDS — PANAMA: Cerro de Garagara, 20-900 m alt. (Bartsch & Morrison, 1942).

Incidostoma impressum (Thompson, 1969)

Neocyclotus (Incidostoma) impressus Thompson, 1969; Zoologica, 54: 75-76; pl. VII, figs. A-C, G (shell); pl. I, fig. L (operculum); text-fig. 12, C-D (male reproductive system); text-fig. 14, C-D (female reproductive system).

TYPE LOCALITY — Along road immediaely east of Nueva Castle [New Castle], Limon Prov., Costa Rica. Holotype FLMNH 20151.

DISTRIBUTION RECORDS — COSTA RICA, Limon Prov.: Pandora. (Thompson, 1969).

Incidostoma irregulare (Pfeiffer, 1855)

Cyclostoma (Cyclotus) irregulare Pfeiffer, 1855; Proc. Zool. Soc. London: 117.

Cyclotus irregularis (Pfeiffer). Reeve, 1864; Conch. Iconica, 14: pl. 4, fig. 18 (shell).

Cyclotus (Aperostoma) irregularis (Pfeiffer). Von Martens, 1890: 3 — Von Martens, 1900: 596.

Poteria (Neocyclotus) irregulare (Pfeiffer). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137): 43.

Aperostoma (Aperostoma) irregulare (Pfeiffer). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 236; pl. 33, fig. 4 (shell).

Neocyclotus (Incidostoma) irregulare (Pfeiffer). Thompson, 1969; Zoologica, 54: 74.

TYPE LOCALITY — Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA: Cache; Talamanca (Von Martens, 1890); San Mateo, 250 m alt.; Ravine of Vijaqual in the valley of San Savenque; El Pital, in the alley of the Rio Naranjo; Alto de Mano Tigre, in the valley of the Rio Grande de Terraba; Quebrada de Tocori, in the valley of the Rio Paquera (Von Martens, 1900). Limon Prov.: Pandora (Thompson, 1969).

Incidostoma pittieri (Von Martens, 1900)

Cyclotus (Aperostoma) irregularis pittieri Von Martens, 1890: 597.

Poteria (Noecyclotus) irregularis pittieri (Von Martens). H. B. Baker, 1923; Occ. Pap. Mus. Zool. Univ. Mich., (137) 41.

Aperostoma (Aperostoma) pittieri (Von Martens). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 236-237.

TYPE LOCALITY — Salinas Bay northwestern Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Incidostoma portobellense (Bartsch & Morrison, 1942)

Aperostoma (Aperostoma) portobellense Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 242; pl. 34, figs. 7-9 (shell).

TYPE LOCALITY — Porto [Puerto] Bello, Panama. Holotype USNM 251434.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Genus Dicrista Thompson, 1969

Dicrista Thompson, 1969; Zoologica, 54: 42-43.

TYPE SPECIES — Dicrista liobasis Thompson, 1969 (by original designation).

DISTRIBUTION — West coast of Mexico from Sinaloa south to Oaxaca, Costa Rica (?).

TAXONOMY — Seven species are recognized.

Dicrista cooperi (Tryon, 1863)

Cyclotus cooperi Tryon, 1863; Proc. Acad. Nat. Sci. Phila.: 281; pl. 2, fig. 2 (shell).

Mexcyclotus cooperi (Tryon). Bartsch & Morrison, 1842: 180; pl. 24, figs. 10-12 (shell).

Mexcyclotus lutescens (Pfeiffer). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 181; pl. 24, figs. 12-15 — Solem, 1956: 55-56; pl. 5, figs. 12-13, 16.

Dicrista cooperi (Tryon). Thompson, 1969; Zoologica, 54: 43-47; pl. II, figs. A-C (shell); pt. 1, fig. B; text-fig. 4, A (operculum).

TYPE LOCALITY — Near Mazatlán, Sinaloa. Holotype ANSP 13019.

DISTRIBUTION RECORDS — SINALOA: Rosario. JALISCO: Hacienda de Istapa; San Sebastian. COLIMA: 7.6 mi. NNE of Manzanilla, 200 ft. alt. GUERRERO: Zihuatenajo. OAXACA: no specific locality. COSTA RICA: no specific locality. (All records from Thompson, 1969.)

Dicrista damianensis (Solem, 1956)

Mexcyclotus damianensis Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 57-58; pl. 5, fig. 11; pl. 6, figs. 13, 18 (shell).

Dicrista damianensis (Solem). Thompson, 1969; Zoologica, 54: 47-48; pl. III, figs. D-F (shell); pl. I, fig. C; text-fig. 4, B (operculum).

TYPE LOCALITY — Michoacán, 1 mile north of San Pedro Damian Naranjistillo (103º08’ W, 18º18’ N). Holotype UMMZ 184837.

DISTRIBUTION RECORDS — MICHOACÁN: known only from the type locality.

Dicrista flavescens Thompson, 1969

Dicrista flavescens Thompson, 1969; Zoologica, 54: 49-51; pl. II, figs. G-I (shell); pl. I, fig. E; text-fig. 4, D (operculum); text-figs. 5, E-G (male reproductive system).

TYPE LOCALITY — Guerrero, 7.8 miles south of Mazatlán, 3500 ft. alt. Holotype FLMNH 20197.

DISTRIBUTION RECORDS — GUERRERO: known only from the type locality.

Dicrista indentata Thompson, 1969

Dicrista indentata Thompson, 1969; Zoologica, 54: 51-52; pl. II, figs. D-F (shell); pl. I, fig. F; text-fig. 4, E (operculum).

TYPE LOCALITY — Michoacán, 10.0 miles southeast of San Vicente, 200 ft. alt. Holotype FLMNH 20191.

DISTRIBUTION RECORDS — MICHOACÁN: known only from the type locality.

Dicrista liobasis Thompson, 1969

Dicrista liobasis Thompson, 1969; Zoologica, 54: 48-49; pl. III, figs. A-C; pl. I, fig. 13; text-fig. 4, C (operculum); text-figs. 5, A-B (male reproductive system); text-figs. 6, A-C (female reproductive system).

TYPE LOCALITY — Jalisco, a limestone sink 6.0 miles southwest and 6.6 miles east of Pihuamo [ca. 19°25 N, 103º38 W]; 2000 ft. alt. Holotype FLMNH 20194.

DISTRIBUTION RECORDS — JALISCO: known only from the type locality.

Dicrista petersi (Solem, 1956)

Mexcyclotus petersi Solem, 1956; Proc. Acad. Nat. Sci. Phila, 108: 56-57; pl. 5, fig. 9; pl. 6, figs. 14-17 (shell).

Dicrista petersi (Solem). Thompson, 1969; Zoologica, 54: 52; p. IV, figs. A,_D (shell); pl. I, fig. G, text-fig. 4, F (operculum).

TYPE LOCALITY — Michoacán, La Placita [Sulatillo] (18º23’ N, 103º37’ W). Holotype UMMZ 184836.

DISTRIBUTION RECORDS — MICHOACÁN: known only from the type locality.

Dicrista rugosa Thompson, 1969

Dicrista rugosa Thompson, 1969; Zoologica, 54: 52-53; pl. IV, figs. E,_G (shell); pl. 1, fig. H; text-fig. 4, G (operculum); text-fig. 5, C-D (male reproductive system).

TYPE LOCALITY — A small limestone knoll 1.4 miles east of Colima; 1800 ft. alt. Holotype FLMNH 20199.

DISTRIBUTION RECORDS — COLIMA: known only from the type locality.

Genus Xenocyclus Thompson, 1969

Xenocyclus Thompson, 1969; Zoologica, 54: 55-56.

TYPE SPECIES — Xenocyclus patulus Thompson, 1969 (by original designation).

DISTRIBUTION — Colima, Mexico.

TAXONOMY — A single species is recognized.

Xenocyclus patulus Thompson, 1969

Xenocyclus patulus Thompson, 1969; Zoologica, 54: 54-56: pl. 5, figs. A-D (shell); pl. I, fig. A, text-fig. 4, H (operculum); text-figs. 5, H-I (male reproductive system); text-fig. 6, D (female reproductive system).

TYPE LOCALITY — A limestone ridge 0.3 miles southeast of Tamala, 500 ft. alt. Holotype FLMNH 20185.

DISTRIBUTION RECORDS — COLIMA: known only form the type locality.

Genus Amphicyclotus Crosse & Fischer, 1879

Amphicyclotus Crosse & Fischer, 1879; Jour. de Conchyl., 27: 46 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 183-184 — Morrison, 1955; Jour. Wash. Acad. Sci., 45: 160 — Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 43-44 — Thompson, 1969; Zoologica, 54: 56.

Megacyclotus Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 181.

TYPE SPECIES — Amphicyclotus: Cyclostoma (Cyclophorus) boucardi Pfeiffer, 1856, by original designation. Megacyclotus: Cyclostoma ponderosum Pfeiffer, 1851.

DISTRIBUTION — Southeast Mexico, Guatemala, Belize, El Salvador and Honduras.

TAXONOMY — Eight species and two subspecies are recognized.

Amphicyclotus boucardi (Pfeiffer, 1856)

Cyclostoma (Cyclophorus) boucardi Pfeiffer, 1856; Proc. Zool. Soc. London, 24: 323; pl. 35, fig. 25.

Cyclophorus boucardi (Pfeiffer). Pfeiffer, 1858; Monogr. pnemon. viv., 2: 65.

Amphicyclotus boucardi (Pfeiffer). Fischer & Crosse, 1880:¨pl. 35, fig. 1 (shell) — Fischer & Crosse, 1888: 142 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 184-185; pl. 24, figs. 4-6 (shell).

Cyclophorus (Amphicyclotus) boucardi (Pfeiffer). Von Martens, 1890: 6.

TYPE LOCALITY — Cordova [Cordoba], Veracruz.

DISTRIBUTION RECORDS — VERACRUZ: known only from the type locality.

Amphicyclotus maleri Crosse & Fischer, 1883

Amphicyclotus maleri Crosse & Fischer, 1883: 102 — Fischer & Crosse, 1886: pl. 41, figs. 3-3c (shell) — Fischer & Crosse, 1888: 145 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 185-186; pl. 24, figs. 7-9 (shell).

Cyclophorus (Amphicyclotus) maleri (Crosse & Fischer). Von Martens, 1890: 6.

TYPE LOCALITY — Tabasco.

DISTRIBUTION RECORDS — OAXACA: Santa Efigenia, Tehuantpec (Von Martens, 1890). TABASCO: Poaná Mountains (Solem, 1956a).

Amphicyclotus megaplanus Morrison, 1955

Amphicyclotus megaplanus Morrison, 1955; Jour. Wash. Acad. Sci., 45: 160; figs. 29-31 (shell) — Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 46 — Thompson, 1969; Zoologica, 54: 63-64; pl. 1, fig. I (operculum); text-figs. 8, C-D (male reproductive system).

TYPE LOCALITY — Forests of Ocote, near Ocozocoantla [Ocozocoautla], Chiapas; 600-1000 m alt. Holotype USNM 618777.

DISTRIBUTION RECORDS — CHIAPAS: 15.8 mi. NW of Ocozocoautla, 2700 ft. alt. (Thompson, 1969).

Amphicyclotus palenquensis (Pilsbry, 1935)

Aperostoma (Amphicyclotus) palenquense Pilsbry, 1935; Proc. Acad. Nat. Sci. Phila., 87: 3-4; pl. 1, figs. 3, 3a, 3b (shell).

Megacyclotus palenquensis (Pilsbry). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 183; pl. 24, figs. 16-18 (shell).

Amphicyclotus (A.) palenquensis (Pilsbry). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 44-45.

TYPE LOCALITY — District of Palenque, Chiapas. Holotype ANSP 106344.

DISTRIBUTION RECORDS — CHIAPAS: Palenque. VERACRUZ: Motzorongo (Solem, 1956a).

Amphicyclotus parvus Thompson, 1963

Amphicyclotus parvus Thompson, 1963: 20-22; pl. II, figs. 4-7 (shell) — Thompson, 1969; Zoologica, 54: 63; text-figs. 8, A-B (male reproductive system); text-fig. 9, C (female reproductive system).

TYPE LOCALITY — Hacienda Monte Cristo, Metapan, Dept. Santa Ana, El Salvador; 2200 m alt. Holotype UMMZ 195882.

DISTRIBUTION RECORDS — EL SALVADOR: known only from the type locality.

Amphicyclotus paulsonorum Thompson, 1969

Amphicyclotus paulsonorum Thompson, 1969; Zoologica, 54: 61-63; pl. VI, figs. D-F (shell); text-figs. 8, E-F (male reproductive system); text-fig. 9 A (female reproductive system).

TYPE LOCALITY — A ravine 4.2 miles northwest of Escuintla, Chiapas; 300 ft. alt. Holotype FLMNH 20180.

DISTRIBUTION RECORDS — CHIAPAS: 21.3 mi. NW of Huixtla, 300 ft. alt.; 32.5 mi. NW of Huixtla, 200 ft. alt.; 10 mi. NW of Pijijiapan, 100 ft. alt. (Thompson, 1969).

Amphicyclotus ponderosus (Pfeiffer, 1851)

Cyclostoma ponderosum Pfeiffer, 1851; Proc. Zool. Soc. London: 283.

Cyclophorus ponderosus (Pfeiffer). Pfeiffer, 1952; Monogr. pneumon. viv., 1: 97.

Amphicyclotus ponderosus (Pfeiffer). Fischer & Crosse, 1880: pl. 35, fig. 3 (shell) — Fischer & Crosse, 1888: 147 — Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 46.

Cyclophorus (Amphicyclotus) ponderosus (Pfeiffer). Von Martens, 1890: 5 — Von Martens, 1900: 597.

Megacyclotus ponderosus (Pfeiffer). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 182-183; pl. 24, figs. 19-21 (shell).

TYPE LOCALITY — Not given.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: Coban; Senahu (Von Martens, 1890); San Juan (Von Martens, 1900); Chama; Secanquin, 550 m alt. (Bartsch & Morrison, 1942).

Amphicyclotus texturatus texturatus (Sowerby, 1850)

Cyclostoma texturatum Sowerby, 1850; Thesaurus conchyliorum (suppl.): 160; pl. 31A, fig. 303 (shell).

Amphicyclotus texturatus (Sowerby). Fischer & Crosse, 1880: pl. 35, figs. 2-2b (shell) — Fischer & Crosse, 1886: 144 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 186; pl. 24, figs. 1-3 (shell).

Amphicyclotus texturatus texturatus (Sowerby). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 45.

TYPE LOCALITY — Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: Coban; Finca Providencia; Finca Caluchen; Finca Samac (Solem, 1956a). CHIAPAS: Chiquihuite; Soconusco (Solem, 1956a).

Amphicyclotus texturatus goldfussi (Boettger, 1892)

Aperostoma (Amphicyclotus) goldfussi Boettger, 1892; Nach. Blätt. Deut. Malak. Ges., 24: 203.

Amphicyclotus goldfussi (Boettger). Kobelt & Möllendorff, 1907; Nach. Blätt. Deut. Malak. Ges., 29: 139 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 184.

Cyclophorus (Amphicyclotus) texturatus goldfussi (Boettger). Von Martens, 1900: 598.

Amphicyclotus texturatus goldfussi (Boettger). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 145.

TYPE LOCALITY — San Pedro Sula, Honduras.

DISTRIBUTION RECORDS — HONDURAS, Dept. Colon: Tarral (Solem, 1956a).

Amphicyclotus texturatus spiralis Thompson, 1969

Amphicyclotus (A.) texturatus texturatus (Sowerby). Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 45 (in part).

Amphicyclotus texturatus spiralis Thompson, 1969; Zoologica, 54: 59-61; pl. VI, figs. A-C (shell); text-figs. 7, A-C (male reproductive system); text-fig. 9, D (female reproductive system).

TYPE LOCALITY — Coffee grove 4.7 mi. north-northeast of Huixtla, Chiapas; 600 ft. alt. Holotype FLMNH 20176.

DISTRIBUTION RECORDS — CHIAPAS: Escuintla (Solem, 1956a); 12.7 mi. NNE of Huixtla, 1500 ft. alt.; 14.6 mi. NNE of Huixtla, 2100 ft. alt. (Thompson, 1969).

Genus Barbacyclus Bartsch & Morrison, 1942

Barbacyclus Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 175 — Thompson, 1969; Zoologica, 54: 64.

TYPE SPECIES — Cyclophorus underwoodi Da Costa, 1900, by original designation.

DISTRIBUTION — Costa Rica.

TAXONOMY — Three species are recognized.

Barbacyclus boucardi (Angas, 1878)

Cyclotus boucardi Angas, 1878; Proc. Zool. Soc. London: 73; pl. 5, figs. 3-4 (shell) — Von Martens 1890: 5.

Neocyclotus (Neocyclotus) boucardi (Angas). Kobelt & Möllendorff, 1907; Nach. Blätt. Deut. Malak. Ges., 29: 137.

Aperostoma princeps angasianum Pilsbry, 1935: 3.

Barbacyclus boucardi (Angas). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 177-178; pl. 23, figs. 4-6 (shell).

TYPE LOCALITY — San Carlos, Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA, Prov. Limon: La Emilia, nr. Guapiles (Pilsbry, 1935).

Barbacyclus princeps (Pilsbry, 1935)

Cyclotus boucardi Angas, 1879; Proc. Zool. Soc. London: 483 (not Cyclotus boucardi Angas, 1878: 73).

Aperostoma (Amphicyclotus) princeps Pilsbry, 1935: 3; pl. 1, figs. 1-1b (shell).

Barbacyclus princeps (Pilsbry). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 175-176; pl. 23, figs. 1-3 (shell) — Thompson, 1969; Zoologica, 54: 64; text-fig. 7, D-E (male reproductive system).

TYPE LOCALITY — Mouth of the Banana River, 5 miles from Limón, Costa Rica. Holotype ANSP 12930.

DISTRIBUTION RECORDS — COSTA RICA, Dept. Limon: Moin Hill (Thompson, 1969).

Barbacyclus underwoodi (Da Costa, 1900)

Cyclophorus underwoodi Da Costa, 1900; Proc. Malac. Soc. London, 4: 67; pl. 7, figs. 5-8 (shell).

Cyclophorus (Amphicyclotus) underwoodi Da Costa. Von Martens, 1900: 598.

Amphicyclotus underwoodi (Da Costa). Kobelt, 1902; Das Tierreich, Cyclophoridae: 257 — Kobelt, 1912; in Martini & Chemnitz Syst. Conch. Cab., 1: 919; pl. 135, figs. 2-4 (shell).

Babacyclus underwoodi (Da Costa). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 176-177; pl. 23, figs. 7-9 (shell).

TYPE LOCALITY — Carillo, Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Genus Calacyclotus Bartsch & Morrison, 1942

Calacyclotus Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 178.

TYPE SPECIES — Amphicyclotus olssoni Pilsbry, 1926 by original designation.

DISTRIBUTION — Panama and immediately adjacent Colombia.

TAXONOMY — Two species are known.

Calacyclotus atratensis Bartsch & Morrison, 1942

Calacyclotus atratensis Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 179; pl. 23, figs. 10-12 (shell).

TYPE LOCALITY — Mountains near the mouth of the Atrato River in Colombia. Holotype USNM 206291.

DISTRIBUTION RECORDS — PANAMA-COLOMBIA: known only from the type locality. The Atrato River lies on the border between Colombia and Panama.

Calacyclotus olssoni (Pilsbry, 1926)

Amphicyclotus olssoni Pilsbry, 1926; Proc. Acad. nat. Sci. Phila, 78: 65-66; pl. 9, figs 13-15 (shell).

Calacyclotus olssoni (Pilsbry). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 178-179.

TYPE LOCALITY — Near Lagarto, Dept. Colon, Panama. Holotype ANSP 47354.

DISTRIBUTION RECORDS — COLOMBIA, Dept. Choco: Acandí, Gulf of Atrato (Bartsch & Morrison, 1942).

Neocyclotidae of doubtful occurrence in Mexico and Central America

Mexcyclotus lutescens (Pfeiffer, 1851)

Cyclosytoma lutescens Pfeiffer, 1851; Proc. Zool. Soc. London: 250.

Mexcyclotus lutescens (Pfeiffer). Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 179 — Solem, 1956; Proc. Acad. Nat. Sci. Phila., 108: 55-56 — Thompson, 1969; Zoologica, 54: 61-62.

The species name is a nomen dubium (Thompson, 1969; Zoologica, 54: 41-42). As a consequence the genus name is also a nomen dubium. The species was first described from Brazil, but was later credited to Mexico. The syntypes lack opercula, and the identity of the species cannot be determined with certainty. This, coupled with the doubtful occurrence of the species, make identification of populations untenable.

Family DIPLOMMATINIDAE Pfeiffer, 1856

DISTRIBUTION — The family is widely distributed on islands along the western Pacific rim, on the eastern Asian mainland and in the Neotropical Region. The family includes numerous genera and species. A single genus occurs in the Neotropical Region.

Genus Adelopoma Doering, 1884

Adelopoma Doering, 1884; Bol. Acad. Nac. Cien. Cordoba, 7: 457 — Ancey, 1899; Jour. de Conchyl., 47: 194-197 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 148.

TYPE SPECIES — Adelopoma tucma Doering, 1884.

DISTRIBUTION — Eastern Mexico south to Argentina.

TAXONOMY — Eight species are recognized. Two occur in the study area.

Adelopoma costaricense Bartsch & Morrison, 1942

Adelopoma costaricense Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 150; pl. 40, fig. 4 (shell) — Pérez & López, 2001; Malac. Rev., 33/34: 92.

TYPE LOCALITY — Santa María, Costa Rica; 1550 m alt. Holotype USNM 516034.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality. NICARAGUA, Dept. Jinotega: Apanés; Cartuja; Selva Negra (Pérez & López, 2001).

Adelopoma stolli (Von Martens, 1890)

Diplommatina stolli Von Martens, 1890: 20-21; pl. 1, fig. 19-19b (shell).

Palaina (Eupalaina) stolli (Von Martens). Kobelt & Moellendorff, 1898: 133.

Adelopoma Stolli (Von Martens). Ancey, 1899; Jour. de Conchyl., 47: 197 — Kobelt, 1902: 480 — Hinkley, 1907; Nautilus, 21: 78 — Bartsch & Morrison, 1942; Bull. U. S. Nat. Mus., 181: 149; pl. 40, figs. 2-3 (shell) — Correa-Sandoval, Gutierrez & Reza, 1998; Acta Zool. Mex., n. s. (73): 3 — Pérez & López, 2001; Malac. Rev., 33/34: 92.

TYPE LOCALITY — NW Guatemala: in the District Cholhuitz, on the slope of the Volcán de Santa María, at the plantation Helvitia. I have not located this place with certainty. The Global Gazetteer Version 2.1. Jan 26, 2006, lists Cholhuitz, Dept. Huehuetenango (15.87 N, 91.55 W).

DISTRIBUTION RECORDS — Reported from northeastern Mexico, Guatemala and Nicaragua. GUATEMALA: known only from the type locality. NICARAGUA, Dept. Jinotega: Puene Pra; Las Pilas; La Cartuja (Pérez & López, 2001). SAN LUÍS POTOSÍ: 15.5 km SW of Tamazunchale, 140 m alt. (21°12’26” N, 98°53’25” W); Vega Larga, 5 km SW of Tamazunchale, 120 m alt. (21°14’23” N, 98°50’31” W); Vega Larga, 140 m alt. (21°13’24” N, 98°50’00” W) (Correa-Sandoval, et al, 1998). TAMAULIPAS: Tampico, in river drift (Hinkley, 1907).


Superfamily CERITHIOIDEA

Family PLEUROCERIDAE Fischer, 1885

DISTRIBUTION — North and South America, east Asia, and Africa. The geographic restrictions of the family are poorly understood because of the unsatisfactory taxonomy and phylogeny of the many genera placed here.

TAXONOMY — Ten genera are recognized in North America. One occurs in Mexico.

Genus Lithasiopsis Pilsbry, 1910

Lithasiopsis Pilsbry, 1910; Proc. Malac. Soc. London, 9: 47-50 — Thompson, 1959; Occ. Pap. Univ. Mich. Mus. Zool., (600): 1.

Pachychilus (Oxymelania). Morrison, 1954; Proc. U. S. Nat. Mus., 103: 365.

TYPE SPECIES — Litasiopsis hinkleyi Pilsbry, 1910.

DISTRIBUTION — Confined to the Rio Panuco system and the Rio Guayalejo system of northeastern Mexico.

TAXONOMY — Four species are recognized.

Lithasiopsis crassus Thompson, 1959

Lithasiopsis crassa Thompson, 1959; Occ. Pap. Univ. Mich. Mus. Zool., (600): 2; text-figs. a, c-f; pl. 1, figs. a-f (shell).

TYPE LOCALITY — Rio Sabinas [Rio Guayalejo system], Pano Ayuctle, 5 miles NE of Gomez, Farias, Tamaulipas, Mexico. Holotype UMMZ 195130.

DISTRIBUTION RECORDS — TAMAULIPAS: known only from the Rio Sabinas (Thompson, 1959).

Lithasiopsis darnelli Thompson, 1959

Lithasiopsis darnelli Thompson, 1959; Occ. Pap. Univ. Mich. Mus. Zool., (600): 4; text-figs. b, g-j; pl. 1, figs. g-l (shell).

TYPE LOCALITY — Rio Sabinas [Rio Guayalejo system], above La Unión, Tamaulipas, Mexico. Holotype UMMZ 195098.

DISTRIBUTION RECORDS — MEXICO. Tamaulipas: known only from the Rio Sabinas (Thompson, 1959).

Lithasiopis hinkleyi Pilsbry, 1910

Lithasiopis hinkleyi Pilsbry, 1910; Proc. Malac. Soc. London, 9: 48; figs. 1-3.

TYPE LOCALITY — Coy River [Rio Panuco system], San Luís Potosí. Holotype in the ANSP.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Lithasiopsis mexicanus Pilsbry, 1910

Lithasiopsis mexicanus Pilsbry, 1910; Proc. Malac. Soc. London, 9: 49; fig. 4.

TYPE LOCALITY — Montezuma [= Moctezuma] River [Rio Panuco system], at the ford, a short distance above Tampamolón, San Luís Potosí. Cotype in the ANSP.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Family PACHYCHILIDAE Troschel, 1857

DISTRIBUTION — Mexico south to northern South America, southeastern Asia, Africa.

TAXONOMY — As with the Pleuroceridae, the geographic, morphological, taxonomic, and phylogenetic parameters relating to this family remain poorly understood. Two genera are recognized in Mexico and Central America.

Genus Amnipila Pilsbry, 1956

Amnipila Pilsbry, 1956, Proc. Acad. Nat. Sci. Phila., 108: 38.

TYPE SPECIES — Pachychilus pila Pilsbry & Hinkley, 1910.

DISTRIBUTION — Rio Tamasopo, San Luís Potosí, Mexico.

TAXONOMY — The genus is monotypic.

Amnipila pila (Pilsbry & Hinkley, 1910.

Pachychilus pila Pilsbry & Hinkley, 1910, Proc. Acad. Nat. Sci. Phila., 61: 521; pl. 24, figs. 1-5.

Amnipila pila (Pilsbry & Hinkley). Pilsbry, 1956, Proc. Acad. Nat. Sci. Phila., 108: 38-38; text-fig. 4; pl. 4, figs. 7-9.

TYPE LOCALITY — Tamosopo River above and below the natural Bridge, near Verastuagu, San Luís Potosí, Mexico. Holotype ANSP 99559 (Pilsbry, 1956).

DISTRIBUTION RECORDS — MEXICO. San Luís Potosí: known only from the immediate vicinity of the type locality.

Genus Pachychilus I. Lea and H. C. Lea, 1850

Pachychilus I. and H. C. Lea, 1850; Proc. Zool. Soc. London: 179 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 19-56 — Fischer and Crosse, 1892; Mission Sci. Mex., II: 320-371 — Von Martens, 1899; Biol. Cent. Amer.: 435-464 — Morrison, 1954; Proc. U. S. Nat. Mus., 103: 364-367.

Cercimelania Crosse and Fischer, 1892; Miss. Sci. Mex., II: 327, 328, 340.

Sphaeromelania Rovereto, 1899; Atti. Soc. Ligust. Sci. Nat. Geogr., 10: 109 (substitute name for Pachychilus).

DISTRIBUTION — Eastern Mexico from Tamaulipas south to the Isthmus of Tehuantepéc and from there southeast along east and west coast drainages at lower elevations to Nicaragua. From there the range is disjunct to the area near Puerto Cabello, Venezuela. Three species occur in Cuba.

TAXONOMY — Pachychilus are large, handsome aquatic snails. Generally they are abundant, and they are the most conspicuous invertebrates present in streams and lakes where they occur. The snails have very limited dispersal ability. Populations are limited genetically and geographically, and numerous forms occur in nature. Because of their abundance and conspicuous appearance specimens found their way into the laboratories of early European and American naturalists. Numerous specific and subspecific names were proposed to account for the observed variation. Whether these represent valid taxa or not remains to be determined. For the most part the taxonomic arrangement used herein follows Von Martens (1899), with subsequently described species inserted where it seems appropriate. Fischer & Crosse (1892) provide an exhaustive synonymy of the species known to then. Von Martens (1899) summarizes subsequent literature. The reader is referred to the monographs by Reeve (1861), Brot (1874), Fischer & Crosse (1892) and Von Martens (1899) for aid in identifying the earlier known species.

Subgenus Pachychilus I. Lea and H. C. Lea, 1850

Pachychilus I. Lea & H. Lea, 1850; Proc. Zool. Soc. London: 179.

Cercimelania Fischer & Crosse, 1892; Miss. Sci. Mex., II: 327, 328, 340.

TYPE SPECIES — Melania laevissima Sowerby, 1824 (Reeve, 1861; Conch. Icon. (Melania): pl. 18, fig. 126). Cercimelania: Melania liebmanni Philippi, 1848.

DISTRIBUTION — Eastern Mexico from Veracruz south to Nicaragua. One species, Pachychilus laevissimus, occurs in Venezuela. Three species occur in Cuba.

TAXONOMY — Fifteen species and five subspecies have been proposed for members of this subgenus.

Pachychilus (Pachychilus) apis (Lea, 1850)

Melania apis Lea, 1850; Proc. Zool. Soc. London: 90 — Reeve, 1861; Conch. Icon. (Melania): pl. 38, fig. 266 — Brot, 1974; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 40; pl. 5, fig. 3.

Pachychilus apis (Lea). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 356 — Von Martens, 1899; Biol. Cent. Amer.: 455.

TYPE LOCALITY — Vera Cruz, in marshy places.

DISTRIBUTION RECORDS — VERACRUZ: known only from the type locality.

Pachychilus (Pachychilus) chrysalis chrysalis (Brot, 1872)

Melania chrysalis Brot, 1872; Mátereiaux fam. Melaniens, 3: 39: pl. 2, fig. 5 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 47: pl. 5, fig. 11.

Pachychilus chrysalis (Brot). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 342; pl. 51, figs. 8, 8a-c — Pilsbry, 1893; Proc. Acad. Nat. Sci. Phila., 44: 340 — Von Martens, 1899; Biol. Cent. Amer.: 457; pl. 27, figs. 6-9 (juvs.), figs.15-18 (shell) — Von Martens, 1901; Biol. Cent. Amer.: 646.

Pachychilus chrysalis var. vulneratus Fischer & Crosse, 1892; Miss. Sci. Mex., II: 342; pl. 51, figs. 9, 9a, 10, 10a.

Pachychilus vulneratus Fischer & Crosse. Pilsbry, 1900; Nautilus, 13: 139.

Pachychilus larvatus Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 336; pl. 34, figs. 11, 11a-c — Fischer & Crosse, 1892; Miss. Sci. Mex., II: 344.

TYPE LOCALITIES — Melania chrysalis: not given. Pachychilus chrysalis var. vulneratus: San Pedro Gineta, Isthmus of Tehuantepec, Oaxaca. Pachychilus larvatus: San Pedro Gineta, Isthmus of Tehuantepec, Oaxaca.

DISTRIBUTION RECORDS — CHIAPAS: San Pedro Jineta; Ixtacomitan. TABASCO: Teapa; Puyacatengo River, nr. Teapa (Pilsbry, 1900). NICARAGUA: Lago de Managua (Von Martens, 1901).

Pachychilus (Pachychilus) chrysalis nympha Von Martens, 1899

Pachychilus chrysalis var. nympha Von Martens, 1899; Biol. Cent. Amer.: 457; pl. 27, figs. 12-14.

TYPE LOCALITY — Rio Sucio, El Salvador.

DISTRIBUTION RECORDS — EL SALVADOR: known only from the type locality.

Pachychilus (Pachychilus) corvinus corvinus (Morelet, 1849)

Melania corvina Morelet, 1849; Test. Noviss., I: 26 — Reeve, 1861; Conch. Icon. (Melania): pl. 19, fig. 135b. Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 36; pl. 5, fig. 1.

Pachycheilus corvinus (Morelet) — H. & A. Adams, 1854; Gen. Moll.: 298; pl. 31, fig. 7-7b.

Pachychilus corvinus (Morelet). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 336; pl. 52, figs. 7-7c — Pilsbry, 1893; Proc. Acad. Nat. Sci. Phila., 44: 340 — Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 41.

Melania cinerea Morelet, 1849; Test. Noviss., I: 26 — Reeve, 1861; Conch. Icon. (Melania): pl. 35, fig. 235 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 38; pl. 4, figs. 6.

Pachychilus cinereus (Morelet). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 334; pl. 52, figs. 8, 8a-c — Von Martens, 1899; Biol. Cent. Amer.: 459.

Melania panucula Morelet, 1851; Test. Noviss., II: 23 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 27; pl. 3, figs. 3, 3a-b.

Pachychilus panucula (Morelet). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 341; pl. 53, figs. 8, 8a — Von Martens, 1899; Biol. Cent. Amer.: 458.

Melania tumidus Tristram, 1863; Proc. Zool. Soc. London: 413.

Melania tumida Tristram. Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 23.

Pachychilus tumidus (Tristram). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 357.

Pachychilus panucula var. tumidus (Tristram). Von Martens, 1899: 457; pl. 27, fig.5.

Melania mexicana Reeve, 1861; Conch. Icon. (Melania): pl. 18, fig. 129 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 45; pl. 5, fig. 9.

Pachychilus mexicanus (Reeve). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 340.

Pachychilus corvinus var. lutescens Fischer & Crosse, 1892; Miss. Sci. Mex., II: 336; pl. 53, figs. 7, 7a.

TYPE LOCALITIES — Melania corvina: small streams of the Department of Verapaz, Guatemala. Melania cinerea: in the rivers of Cobán, Alta Vera Paz, Guatemala. Melania panucula: rivers of the Department of Petén, Guatemala. Melania tumida: lake of Petén, Guatemala. Melania mexicana: Mexico. Pachychilus corvinus var. lutescens: Cobán, [Dept. Alta Verapaz], Guatemala.

DISTRIBUTION RECORDS — TABASCO: Mountains of Poaná. GUATEMALA, Dept. Alta Verapaz: Chejel; Chama; Tactíc; Cobán; between Chama and Cobán (Hinkley, 1920); Rio de la Pasion system (Goodrich & Van der Schalie, 1937). Dept. Baja Verapaz: Stream of Santa Rosa. Dept. Izabal: Rio Cavech; Rio Dulce near Livingston (Hinkley, 1920). NICARAGUA: Tungla River, nr. Quiquina (Fluck, 1905).

Pachychilus (Pachychilus) corvinus indifferens Crosse & Fischer, 1891

Pachychilus indifferens Crosse & Fischer, 1891; Jour. de Chonchyl., 39: 25 — Fischer & Crosse, 1892; Miss. Sci. Mex., II: 337; pl. 50, figs. 8-8c.

Pachychilus corvinus indifferens Crosse & Fischer. Goodrich & Van der Schalie, 1937; Misc. Pub Univ. Mich. Mus. Zool., (34): 41.

TYPE LOCALITY — Rio Motagua, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Baja Verapaz: Rio Motagua. Dept. Petén: Lago de Petén; Lago de Eckibix (Goodrich & Van der Schalie, 1937).

Pachychilus (Pachychilus) explicatus Fischer & Crosse, 1892

Pachychilus indifferens var. explicata Fischer & Crosse, 1892; Miss. Sci. Mex., II: 337; pl. 53, figs. 9, 9a (10, 10a).

Pachychilus explicatus Fischer & Crosse. Von Martens, 1899; Biol. Cent. Amer.: 459.

TYPE LOCALITY — Rio Machaquila, Dept. Petén, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Petén: known only from the type locality.

Pachychilus (Pachychilus) hinkleyi (Marshall, 1921)

Sphaeromelania hinkleyi Marshall, 1921; Proc. U. S. Nat. Mus., 58: 301; pl. 17, figs. 4-13.

TYPE LOCALITY — Tsalbha River, Chamá, Dept. Alta Verapaz, Guatemala. Holotype USNM 336412.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: Chama (Hinkley, 1920).

Pachychilus (Pachychilus) indiorum (Morelet, 1849)

Melania indiorum Morelet, 1849; Test. Noviss., I: 25.

Melania laevissima Sowerby. Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 34; pl. 4, fig. 5b.

Pachycheilus laevissimus (Sowerby). H. & A. Adams, 1854: 299; pl. 31, fig. 7.

Pachychilus laevissimus (Sowerby). Fischer & Crosse, 338.

Pachycheilus indiorum (Morelet). H. & A. Adams, 1854: 299 — Von Martens, 1899; Biol. Cent. Amer.: 455 — Goodrich & Van der Schalie, 1937: 42.

Melania laevissima var. costato-plicata Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 35; pl. 5, fig. 5.

Pachychilus laevissimus var. costatoplicatus (Brot). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 329; pl. 33, fig. 5.

Pachychilus indiorus var. costatoplicatus (Brot). Von Martens, 1899; Biol. Cent. Amer.: 456.

Pachychilus laevissimus var. varicosus Fischer & Crosse, 1892; Miss. Sci. Mex., II: 329; pl. 53, fig. 6.

Pachychilus indiorum var. varicosus Fischer & Crosse. Von Martens, 1899; Biol. Cent. Amer.: 456.

Melania sallei Reeve, 1861; Conch. Icon. (Melania): pl. 19, fig. 133.

Melania radix Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 30; pl. 3, fig. 5.

TYPE LOCALITIES — Melania indiorum: Near the ruins, Palenque, Chiapas, Mexico. Melania laevissima var. costato-plicata: Palenque, Chiapas. Pachychilus laevissimus var. varicosus: Palenque, Chiapas. Melania sallei: not given. Melania radix: not given.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: La Ceiba (Goodrich & Van der Schalie, 1937); Panzos; Chejel (Hinkley, 1920). Dept. Guatemala: Lago de Amatitlán (Hinkley, 1920). Dept. Izabal: Rio Cavech; Rio Dulce, near Livingston; Jocola; Panzos (Hinkley, 1920). MEXICO, CHIAPAS: Palenque. OAXACA: Isthmus of Tehuantepec. VERACRUZ: San Andres Tuxtla.

Pachychilus (Pachychilus) liebmanni liebmanni (Philippi, 1848)

Melania liebmanni Philippi, 1848: 58; pl. 5, fig. 8 — Reeve, 1961; Conch. Icon. (Melania): pl. 20, fig. 139 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 48; pl. 6, fig. 1.

Pachychilus liebmanni (Philippi). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 347 — Von Martens, 1899; Biol. Cent. Amer.: 453; pl. 27, figs. 1, 2.

TYPE LOCALITY — Mexico.

DISTRIBUTION RECORDS — VERACRUZ: Playa Vicente (Von Martens, 1899).

Pachychilus (Pachychilus) liebmanni gassiesi (Reeve, 1861)

Melania gassiesi Reeve, 1861; Conch. Icon. (Melania): pl. 35, fig. 236.

Pachychilus liebmanni var. gassiesi (Reeve). Von Martens, 1899; Biol. Cent. Amer.: 454.

TYPE LOCALITY — Central America.

DISTRIBUTION RECORDS — Unknown.

Pachychilus (Pachychilus) liebmanni gracilior Von Martens, 1899

Pachychilus liebmanni var. gracilior Von Martens, 1899; Biol. Cent. Amer.: 453.

Melania gassiesi (Reeve) Gassies, 1863: 93 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 47; pl. 5, fig. 12.

Pachychilus gassiesi (Reeve). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 348; pl. 51, fig. 5.

TYPE LOCALITY — Rio Teotalcingo, Oaxaca, Mexico.

DISTRIBUTION RECORDS — OAXACA: known only from the type locality.

Pachychilus (Pachychilus) örstedi örstedi (Mörch, 1860)

Pachychilus örstedi Mörch, 1860; Malak. Blätt., 7: 79 — Von Martens, 1899; Biol. Cent. Amer.: 458; pl. 27, figs. 3-5.

Melania örstedi (Mörch). Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 46; pl. 5, fig. 10.

Pachychilus jansoni H. Adams, 1870. Proc. Biol. Soc. London: 795 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 40.

TYPE LOCALITY — Pachychilus orstedi: Segovia, Nicaragua. Pachychilus jansoni: Chontales, Nicaragua.

DISTRIBUTION RECORDS — HONDURAS, Dept. Coban: Lancetilla (Pilsbry, 1931: 84). NICARAGUA, Dept. Chontales: Chontales. Dept. Matagalpa: Arroyo Alasan, Matagalpa.

Pachychilus (Pachychilus) örstedi planensis (Lea, 1858)

Melania planensis Lea, 1858; Proc. Acad. Nat. Sci. Phila.: 118 — Lea, 1864; Obs. Unionidae, 11: 83; pl. 22, fig. 26 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 33; pl. 4, fig. 3.

Pachychilus örstedi var. planensis (Lea). Von Martens, 1899; Biol. Cent. Amer.: 459.

Pachychilus planensis (Lea). Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 42.

TYPE LOCALITY — Plan and Omoa, valley of the Ulua River, Honduras.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Izabal: Puerto Barrios (Goodrich & Van der Schalie, 1937). HONDURAS: known only from the type locality.

Pachychilus (Pachychilus) pottsianus Hinkley, 1920

Pachychilus pottsianus Hinkley, 1920; Nautilus, 33: 54-55.

TYPE LOCALITY — A small stream near Jocola, Dept. Izabal, Guatemala. Type specimen not designated; presumably in Hinkley Collection, Illinois Museum of Natural History, University of Illinois.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Izabal: known only from the immediate vicinity of the type locality. Jocola was a plantation on the north side of the Lago de Izabel. Pachychila pottsianus was collected from two small rills on a hillside behind Jocola.

Pachychilus (Pachychilus) schumoi Pilsbry, 1931

Pachychilus schumoi Pilsbry, 1931; Nautilus, 44: 84; pl. 7, fig. 1 (shell).

TYPE LOCALITY — Rio Negro {Rio Salinas}, Chamá, Dept. Alta Verapaz, Guatemala. Holotype ANSP 76231.

DISTRIBUTION — GUATEMALA: known only from the type locality.

Pachychilus (Pachychilus) turati (Villa, 1854)

Melania turati Villa, 1854; in Strobel, Giornale di Malacologia, 2: 113 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 39; pl. 5, figs. 2, 2a.

Pachychilus turatii (Villa). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 355; pl. 51, figs. 1, 1a. Von Martens, 1899; Biol. Cent. Amer.: 454; pl. 25, figs. 10-20.

Melania gassiesi Reeve. Strebel, 1873: 37; pl. 4, figs. 35, 35a-b.

TYPE LOCALITY — Not given.

DISTRIBUTION RECORDS — VERACRUZ: Rio Atoyac; Rio Jamapa; Jalapa; near Orizaba; Cordoba (Von Martens, 1899).

Subgenus Pilsbrychilus Morrison, 1952

Pilsbrychilus Morrison, 1952; American Malacological Union News Bulletin and Annual Report (1948): 7 — Morrison, 1954; Proc. U. S. Nat. Mus., 103: 366.

TYPE SPECIES — Pachycheilus dalli Pilsbry, 1896.

DISTRIBUTION — Southern Mexico.

TAXONOMY — A single species is recognized.

Pachychilus (Pilsbrychilus) dalli Pilsbry, 1896

Pachycheilus dalli Pilsbry, 1896; Science, 3: 608 — Pilsbry, 1896; Proc. Acad. Nat. Sci. Phila., 48: 269.

Pachychilus dalli Pilsbry. Von Martens, 1899; Biol. Cent. Amer.: 456; pl. 26, fig. 4.

TYPE LOCALITY — Tehuantepec, Oaxaca, Mexico.

DISTRIBUTION RECORDS — OAXACA: known only from the type locality. The type locality most likely is the Isthmus of Tehuantepec, and not the city. Numerous searches have been made in the area near the city, but without success in finding the species.

Subgenus Glyptomelania Crosse and Fischer, 1892

Glyptomelania Fischer & Crosse, 1892; Miss. Sci. Mex., II: 328, 351 — Von Martens, 1899; Biol. Cent. Amer.: 438 — Morrison, 1954; Proc. U. S. Nat. Mus., 103: 366.

TYPE SPECIES — Melania glaphyra Morelet, 1849.

DISTRIBUTION — Nicaragua, Honduras, El Salvador, and Guatemala north to Chiapas and Tabasco, Mexico.

TAXONOMY — Five species and twelve subspecies are recognized.

Pachychilus (Glyptomelania) glaphyrus glaphyrus (Morelet, 1849)

Melania glaphyra Morelet, 1849; Test. Noviss., I: 24 — Reeve, 1861; Conch. Icon. (Melania): pl. 2, fig. 8.

Pachychilus glaphyrus (Morelet). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 352; pl. 52, fig. 2a — Pilsbry, 1893; Proc. Acad. Nat. Sci. Phila., 45: 339; pl. 14, fig. 5 — Von Martens, 1899; Biol. Cent. Amer.: 444 — Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 39.

TYPE LOCALITY — Not given.

DISTRIBUTION RECORDS — GUATEMALA. Dept. Izabal: Jocolo (Hinkley, 1920). Dept. Alta Verapaz: Arroyo Yalchactilá, Rio de la Passion, ca. 4 miles southwest of La Ceiba (Goodrich & Van der Schalie, 1939). Dept. Petén: Springs of the [Rio] Usumacinta (Fischer & Crosse, 1892; Miss. Sci. Mex., II: 352.

Pachychilus (Glyptomelania) glaphyrus bicarinatus Von Martens, 1901

Pachychilus glaphyrus var. Pilsbry, 1893; Proc. Acad. Nat. Sci. Phila., 45: 339; pl. 14, fig. 6.

Pachychilus glaphyrus var. bicarinatus Von Martens, 1901; Biol. Cent. Amer.: 445.

TYPE LOCALITY — Tabasco.

DISTRIBUTION RECORDS — TABASCO: known only from the type locality.

Pachychilus (Glyptomelania) glaphyrus glaphyroides Fischer & Crosse, 1892.

Melania immanis var. ε Brot; 1874: 22; pl. 2, fig. 1f.

Pachychilus glaphyrus var. ε glaphyroides Fischer & Crosse, 1892; Miss. Sci. Mex., II: 352 — Von Martens, 1899; Biol. Cent. Amer.: 444.

TYPE LOCALITY — Springs of the Rio Usumacinta, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Pachychilus (Glyptomelania) glaphyrus immanis (Morelet, 1851)

Melania immanis Morelet, 1851; Test. Noviss., II: 22 — Reeve, 1861; Conch. Icon. (Melania): pl. 35, fig. 238.

Pachychilus glaphyrus immanis (Morelet). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 351; pl. 53: Figs. 1, 1a — Von Martens, 1899; Biol. Cent. Amer.: 438.

TYPE LOCALITY — Small streams in the Province of Petén, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: Dolores; Cobón; Rio Jacito at Punta Gorda (Von Martens, 1899: 444).

Pachychilus (Glyptomelania) glaphyrus polygonotus (Lea, 1850)

Melania polygonotus Lea, 1850: 195 — Reeve, 1861; Conch. Icon. (Melania): pl. 3, fig. 11.

Pachychilus glaphyrus polygonotus (Lea). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 351 — Von Martens, 1899; Biol. Cent. Amer.: 444.

Pachychilus glaphyrus rovirosai Pilsbry, 1892; Proc. Acad. Nat. Sci. Phila., 44: 153; pl. 8, fig. 10 — Pilsbry, 1893; Nautilus, 7: 62; pl. 1, figs. 9, 10.

TYPE LOCALITIES — Melania polygonotus: “Copan”. Syntypes in the USNM. (It is not clear whether Lea intended Copán, Dept. Santa Barbara, Honduras, or Cobán, Dept. Alta Verapaz, Guatemala, as suggested by Von Martens. If Copán is the type locality it seems highly unlikely that rovirosai could be a synonym of polygonotus as suggested by Von Martens, 1899: 444.) Pachychilus rovirosai: Limón, Tabasco, Mexico. Holotype ANSP.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: Cobán; Dolores (Von Martens, 1899). TABASCO: western brow of the little ridge of the Limon, Poana Mountains (Pilsbry, 1893b).

Pachychilus (Glyptomelania) glaphyrus pyramidalis (Morelet, 1851)

Melania pyramidalis Morelet, 1849; Test. Noviss., I: 25.

Melania opiparis Morelet. Reeve 1861; Conch. Icon. (Melania): pl. 5, fig. 25.

Melania godmani Tristram, 1863: 113.

Pachychilus godmani (Tristram). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 363.

Pachychilus glaphyrus vars. η, θ. Fischer & Crosse, 1892; Miss. Sci. Mex., II: 353; pl. 52, figs. 1, 1a; pl. 53, fig. 4.

Pachychilus glaphyrus pyramidalis (Morelet). Von Martens, 1899; Biol. Cent. Amer.: 446; pl. 25, figs. 2, 3.

TYPE LOCALITIES — Melania pyramidalis: Small streams of the interior of Tabasco. Melania godmani: Lake Petén, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: Panzos (Hinkley, 1920). Dept. Izabal: Jocolo (Hinkley, 1920); Esmeralda (Hinkley, 1920); Livingston (Hinkley, 1920); across the Rio Dulce from Livingston (Hinkley, 1920). Dept. Petén: San Luís; Lake Petén (Von Martens, 1899).

Pachychilus (Glyptomelania) glaphyrus scamnatus Fischer & Crosse, 1892

Pachychilus glaphyrus var. δ scamnatus Fischer & Crosse, 1892; Miss. Sci. Mex., II: 352; pl. 52, fig. 2 — Von Martens, 1899; Biol. Cent. Amer.: 444.

TYPE LOCALITY — Cobán, Alta Verapaz, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Pachychilus (Glyptomelania) glaphyrus opilaris (Morelet, 1851)

Melania opiparis Morelet, 1851: 23.

Pachychilus immanis var. β Brot, 1872; 21; pl. 2, fig. 1b.

Pachychilus glaphyrus var. ζ semilaevis Fischer & Crosse, 1892; Miss. Sci. Mex., II: 352; pl. 53, figs. 2, 2a — Von Martens, 1899; Biol. Cent. Amer.: 445.

Pachychilus glaphyrus var. θ opiparis Fischer & Crosse, 1892; Miss. Sci. Mex., II: 353; pl. 53, fig. 3 — Von Martens, 1899; Biol. Cent. Amer.: 445.

TYPE LOCALITIES — Melania opilaris: Dolores, Dept. Petén, Guatemala. Pachychilus glaphyrus var. ζ semilaevis: Dolores, Dept. Petén, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Pachychilus (Glyptomelania) lacustris lacustris (Morelet, 1849)

Melania lacustris Morelet, 1849; Test. Noviss., I: 25 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 25.

Pachychilus lacustris (Morelet). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 359; pl. 51, figs. 3, 3a; pl. 52, figs. 4, 4a — Von Martens, 1899; Biol. Cent. Amer.: 447.

Pachychilus glaphyrus lacustris (Morelet). Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 40.

TYPE LOCALITY — Lake near Izabal, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Guatemala: Lago de Amatitlán (Hinkley, 1920). Dept. Izabal: Jocolo (Hinkley); Lago de Izabal (Von Martens, 1899).

Pachychila (Glyptomelania) lacustris amphibolus Fischer & Crosse, 1892

Pachychila lacustris var. amphibolus Fischer & Crosse, 1892; Miss. Sci. Mex., II: 360; pl. 52, fig. 3 — Von Martens, 1899; Biol. Cent. Amer.: 447.

Pachychilus lacustris var. pumila Fischer & Crosse, 1892; Miss. Sci. Mex., II: 360: pl. 51, figs. 4, 4a.

Pachychilus lacustris var. pumilus Fischer & Crosse. Von Martens, 1899; Biol. Cent. Amer.: 448.

Pachychilus lacustris var. major Fischer & Crosse, 1892; Miss. Sci. Mex., II: 360 — Von Martens, 448; pl. 25, fig. 8.

Pachychilus lacustris var. terebralis Fischer & Crosse, 1892; Miss. Sci. Mex., II: 360; pl. 52, fig. 3a — Von Martens, 1899; Biol. Cent. Amer.: 448.

Pachychilus lacustris var. eliminatus Fischer & Crosse, 1892; Miss. Sci. Mex., II: 360 — Von Martens, 1899; Biol. Cent. Amer.: 448.

Pachychilus lacustris var. conradi Von Martens, 1899; Biol. Cent. Amer.: 448; pl. 25, figs. 9, 10.

Pachychlus glaphyrus lacustris (Morelet). Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 40.

TYPE LOCALITIES — All of these varieties were described from Lago de Izabal, Dept. Izabal, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Izabal: Lago de Izabal. Dept. Petén: Arroyo Subín; Rio de la Pasion (Goodrich & Van der Schalie, 1937).

Pachychilus (Glyptomelania) largillierti largillierti (Philippi, 1843)

Melania largillierti Philippi, 1843: 62, pl. 2, fig. 10 — Reeve, 1861; Conch. Icon. (Melania): pl. 18, fig. 127 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 31; pl. 4, figs. 1a-c.

Pachychilus largillierti (Philippi) — Fischer & Crosse, 1892; Miss. Sci. Mex., II: 364; pl. 52, figs. 5, 5a — Von Martens, 1899; Biol. Cent. Amer.: 450; pl. 25, fig. 12; pl. 26, fig. 2 — Von Martens, 1901; Biol. Cent. Amer.: 645; pl. 44, fig. 17 — Goodrich & Van der Schalie, 1937: 40-41.

Melania intermedia Von dem Busch, in Philippi, 1844: 160; pl. 3, fig. 4 — Reeve, 1861; Conch. Icon. (Melania): pl. 20, fig. 141.

Melania rusticula Von dem Busch, 1858: 36.

Melania rubicunda Reeve, 1861; Conch. Icon. (Melania): pl. 31, fig. 206.

Melania salvini Tristram, 1863: 413.

Melania salwini Tristram. Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 27 (amended name).

Pachychilus subexaratus Crosse & Fischer, 1891: 219 — Fischer & Crosse, 1892; Miss. Sci. Mex., II: 350; pl. 52, fig. 6.

Pachychilus largillierti var. nodulosus Von Martens, 1899; Biol. Cent. Amer.: 451; pl. 25, fig. 4.

TYPE LOCALITIES — Melania largillierti: not given. Melania intermedia: Lago de Nicaragua. Melania rusticula: not given. Melania rubicunda: not given. Melania salvini: Rio de La Pason, Dept. Alta Verapaz, Guatemala. Pachychilus subexaratus: a small stream near Lago de Izabal, Guatemala. Pachychilus largillierti var. nodulosus; Paso Antonio, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Escuintla: Mirandilla. Dept. Guatemala: Lago de Amatitlan; Rio Michatoya, issuing from the lake; Rio Maria Linda; (Morelet); Paso Antonio, near Torola. Dept. Izabal: Rio Cavech; Plantera (Hinkley, 1920). Dept. Petén: Rio de la Pasion. Dept. Zacapa: Lagarto, near Zacapa. NICARAGUA: Lago de Nicaragua. EL SALVADOR, Dept. San Miguel: Joya.

Pachychilus (Glyptomelania) largillierti stolli Von Martens, 1899

Pachychilus largillierti var. stolli Von Martens, 1899; Biol. Cent. Amer.: 452; pl. 25, figs. 5-9.

TYPE LOCALITY — Environs of Retalhuleu, Dept. Retalhuleu, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Pachychilus (Glyptomelania) obeliscus obeliscus (Reeve, 1861)

Melania obeliscus Reeve, 1861; Conch. Icon. (Melania): pl. 4, figs. 20 — Brot, 1974: 24; pl. 3, fig. 1a.

Pachychilus obeliscus (Reeve). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 358 — Von Martens, 1899; Biol. Cent. Amer.: 446.

TYPE LOCALITY — Honduras.

DISTRIBUTION RECORDS — HONDURAS: unknown.

Pachychilus (Glyptomelania) obeliscus examartus Fischer & Crosse, 1892

Melania obeliscus var. γ Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 24; pl. 3, fig. 1b.

Pachychilus obeliscus var. exarmatus Fischer & Crosse, 1892; Miss. Sci. Mex., II: 358 — Von Martens, 1899; Biol. Cent. Amer.: 447.

TYE LOCALITY — Not given.

DISTRIBUTION RECORDS — Unknown.

Pachychilus (Glyptomelania) obeliscus pyrgiscus Fischer & Crosse,1892

Pachychilus obeliscus var. pyrgiscus Fischer & Crosse, 1892; Miss. Sci. Mex., II: 358; pl. 50, figs. 9a, 9b — Von Martens, 1899; Biol. Cent. Amer.: 447; pl. 25, fig. 6.

TYPE LOCALITY — Not given.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Petén: Lago de Petén.

Pachychilus (Glyptomelania) potomarchus Pilsbry, 1892

Pachychilus potomarchus Pilsbry, 1893; Proc. Acad. Nat. Sci. Phila., 45: 340; pl. 14, fig. 7.

Pachychilus glaphyrus potomarchus Pilsbry. Von Martens, 1899; Biol. Cent. Amer.: 446.

TYPE LOCALITY — Tabasco.

DISTRIBUTION RECORDS — TABASCO: known only from the type locality.

Pachychilus (Glyptomelania) subnodosus (Philippi, 1847)

Melania subnodosa Philippi, 1847: 173; pl. 4, fig. 18 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 29; pl. 3, fig. 5.

Pachychilus subnodosus (Philippi). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 366 — Von Martens, 1899; Biol. Cent. Amer.: 450; pl. 25; figs. 11, 13.

TYPE LOCALITY — Not given.

DISTRIBUTION RECORDS — NICARAGUA, Dept. Managua: Managua (Von Martens, 1899).

Subgenus Oxymelania Fischer & Crosse, 1892

Oxymelania Fischer & Crosse, 1892; Miss. Sci. Mex., II: 328, 366 — Von Martens, 1899; Biol. Cent. Amer.: 461.

Potamanax Pilsbry, 1893; Proc. Acad. Nat. Sci. Phila., 44: 304.

TYPE SPECIES — Oxymelania: Melania schiedeanus Philippi, 1843. Potamanax: Pachychilus (Potamanax) rovirosai Pilsbry, 1893.

DISTRIBUTION — Streams from the Rio Guayalejo system in northeastern Mexico south to the Rio Usumacinta system in Guatemala.

TAXONOMY — Eighteen species and four subspecies are recognized.

Pachychilus (Oxymelania) apheles Thompson, 1967

Pachychilus apheles Thompson, 1967; Nautilus, 81: 26; pl. 28, figs. 1-5.

TYPE LOCALITY — A spring run 14 miles west northwest of Ciudad Valles, on the road to Rio Verde, San Luís Potosí, Mexico. Holotype FLMNH 19756.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Pachychilus (Oxymelania) atratus Pilsbry & Hinkley, 1910

Pachychilus atratus Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 524-525; pl. 23, figs. 13-18 — Pilsbry, 1956, Proc. Acad. Nat. Sci. Phila., 108: 36; pl. 4, figs. 6, 10, 13, 14, 15.

Pachychilus atratus ganinas Pilsbry & Hinkley, 1910; pl. 23, figs. 19, 20 — Pilsbry, 1956, Proc. Acad. Nat. Sci. Phila., 108: 36.

Pachychilus atratus suprastriatus Pilsbry & Hinkley, 1910: 526 — Pilsbry, 1956, Proc. Acad. Nat. Sci. Phila., 108: 36 (as multistriatus).

TYPE LOCALITIES — Pachychilus atratus: Tamasopo River near Verastagu, San Luís Potosí, Mexico; holotype and 3 figured paratypes ANSP 99570 (Pislbry, 1956: 33). Pachychilus atratus ganinas: Ganina [Gallina] River 3 miles SW of San Dieguito, San Luís Potosí; holotype ANSP 99577. Pachychilus atratus suprastriatus: Valles River at Mecos Falls, and some rapids 2 miles west of Mecos, San Luís Potosí; holotype ANSP 99575.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known from the the type localities cited above.

Pachychilus (Oxymelania) corpulentus Thompson, 1967

Pachychilus corpulentus Thompson, 1967; Nautilus, 81: 28; pl. 28, fig. 1-5.

TYPE LOCALITY — Nacimiento de Rio Mante, about 5 miles west of Ciudad Mante, Tamaulipas, Mexico [Rio Guayalejo system]. Holotype FLMNH 19754.

DISTRIBUTION RECORDS — TAMAULIPAS: known only from the type locality.

Pachychilus (Oxymelania) graphium (Morelet, 1849)

Melania graphium Morelet, 1849; Test. Noviss., I: 26 — Reeve, 1861; Conch. Icon. (Melania): pl. 21, fig. 150 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 41, pl. 5, fig. 4.

Pachycheilus graphium (Morelet). H. & A. Adams, 1854: 298.

Pachychilus graphium (Morelet). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 332; pl. 51, figs. 2, 2a — Von Martens, 1899; Biol. Cent. Amer.: 461 — Von Martens, 1901; Biol. Cent. Amer.: 646 — Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 39-40; text-fig. 1: 7 (radula).

Pachychilus cumingi Lea, 1850. Proc. Zool. Soc. London: 179.

Melania renovata Brot, 1862; Matériaux fam. Mélaniens, 1: 43 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 41; pl. 5, fig. 5.

Melania gracilis Tristram, 1863; Proc. Zool. Soc. London: 413.

Pachychilus tristrami Fischer & Crosse, 1892; Miss. Sci. Mex., II: 369.

Pachychilus graphium var. reducta Fischer & Crosse, 1892; Miss. Sci. Mex., II: 333.

Pachychilus graphium var. transcendens Fischer & Crosse, 1892; Miss. Sci. Mex., II: 333; pl. 50, figs. 7, 7a.

TYPE LOCALITIES — Melania graphium: streams of Verapaz. Pachychilus cumingi: Cobán, in large rivers. Melania renovata: not given. Melania gracilis: Lago de Petén. Pachychilus tristrami: Lago de Petén. Pachychilus graphium var. reducta: Verapaz. Pachychilus graphium var. transcendens: in affluents of the Rio Usumacinta, San Miguel Uspatan, Dept. Quiché, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: on road between Cobán and Chamá (Hinkley, 1920). Dept. Izabal: Esmeralda (Hinkley, 1920). Dept. Quiche. Dept. Petén: Lago de Petén. YUCATAN: (Von Martens, 1901).

Pachychilus (Oxymelania) humerosus Pilsbry & Hinkley, 1910

Pachychilus humerosus Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 526

TYPE LOCALITY — Tamasopo River near Verastagua, above and below the Natural Bridge, San Luís Potosí, Mexico. Holotype and paratype ANSP 99579.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Pachychilus (Oxymelania) moctezumensis Pilsbry & Hinkley, 1910

Pachychilus moctezumensis Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 522; pl. 24, figs. 11, 12 — Pilsbry, 1956; Proc. Acad. Nat. Sci. Phila., 108: text-fig. 2 (radula).

TYPE LOCALITY — Moctezuma River at the ford south of Tampamolón, San Luís Potosí, Mexico. Holotype and three figured paratypes ANSP 99568.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Pachychilus (Oxymelania) monachus Pilsbry & Hinkley, 1910

Pachychilus monachus Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 527; pl. 24, figs. 21-25 — Thompson, 1967; Nautilus, 81: pl. 28, figs. 6-10.

TYPE LOCALITY — Coy [Choy?] River, 3 miles south of Los Palmas, San Luís Potosí, Mexico. Holotype and four figured paratypes ANSP 99581.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Pachychilus (Oxymelania) pleurostriatus pleurostriatus (Say, 1831)

Melania pleurostriata Say, 1831; New Harmony Disseminator of Useful Knowledge, December, 1831 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 44.

Pachychilus pleurostriatus (Say). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 370 — Von Martens, 1899; Biol. Cent. Amer.: 449; pl. 26, fig. 1 — Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 523; pl. 23, figs. 1-5 — Pilsbry, 1956; Proc. Acad. nat. Sci. Phila., 108: 32; text-fig. 1 (radula).

Melania rubida Lea, 1856; Proc. Acad. Nat. Sci. Phila.: 145 — Lea, 1864; Obs. Unionidae, 11: 77; pl. 22, fig. 16. — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 341; pl. 34, fig. 2.

TYPE LOCALITY — Melania pleurostriata: not given. Melania rubida: Mexico.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: Rio Coy. A record from Laguna de Chapala, Jalisco is discounted here (Von Martens, 1899).

Pachychilus (Oxymelania) pleurostriatus longus Pilsbry & Hinkley, 1910

Pachychilus pleurostriatus longus Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 524; pl. 23, figs. 11, 12 — Pilsbry, 1956, Proc. Acad. Nat. Sci. Phila., 108: 33.

TYPE LOCALITY — Ganina [Gallina] River, three miles southwest of San Dieguito, San Luís Potosí, Mexico. Holotype and figured paratype ANSP 99583.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Pachychilus (Oxymelania) pleurostriatus tamasopensis Pilsbry & Hinkley, 1910

Pachychilus pleurostriatus tamasopensis Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 524; pl. 23, figs. 6-9 — Pilsbry, 1956, Proc. Acad. Nat. Sci. Phila., 108: 33.

TYPE LOCALITY — A small stream north of the mill south of the Tamasopo Sugar Co., San Luís Potosí, Mexico. Holotype and 4 figured paratypes ANSP 99584.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Pachychilus (Oxymelania) pleaurotoma Pilsbry & Hinkley, 1910

Pachychilus pleaurotoma Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 530; pl. 24, figs. 13-15 — Pilsbry, 1956, Proc. Acad. Nat. Sci. Phila., 108: 37.

TYPE LOCALITY — First rill on the road [from Tampamolón] to the Rio Moctezuma, San Luís Potosí, Mexico. Holotype and figured paratypes ANSP 99592.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: small streams near Tampamolón; Rio Axtla, Xilitla (Pilsbry, 1956).

Pachychilus (Oxymelania) schiedeanus schiedeanus (Philippi, 1843)

Melania schiedeanus Philippi, 1843: 62; pl. 2, fig. 11 — Reeve, 1861; Conch. Icon. (Melania): pl. 15, fig. 101 — Strebel, 1873: 35; pl. 4, figs. 37, 37a. Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 42; pl. 5, figs. 6, 6a.

Pachychilus schiedeanus (Philippi). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 366; pl. 50, figs. 10-10b — Von Martens, 1899; Biol. Cent. Amer.: 462.

TYPE LOCALITY — Small brooks and ditches around the City of Mexico. This occurrence has not been corroborated by subsequent investigations.

DISTRIBUTION RECORDS — VERACRUZ: Misantla; Rio de Misantla; Arroyo Viejo, 3 miles from Misantla; Cordoba; Coatepec.

Pachychilus (Oxymelania) schiedeanus strebelianus Fischer & Crosse, 1892

Melania saussurei (Brot?). Strebel, 1873:36; 43, 43a.

Pachychilus schiedeanus var. strebelianus Fischer & Crosse, 1892; Miss. Sci. Mex., II: 396.

Pachychilus schiedeanus var. strebelianus Fischer & Crosse. Von Martens, 1899; Biol. Cent. Amer.: 462.

TYPE LOCALITY — Streams of Palpoala, close to Misantla, Veracruz; Mexico.

DISTRIBUTION RECORDS — VERACRUZ: known only from the vicinity of the type locality.

Pachychilus (Oxymelania) saussurei (Brot, 1874)

Melania saussurei Brot; 1860; in Rev. Zoology: 264; pl. 17, fig. 11 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 43; pl. 5, fig. 7.

Pachychilus saussurei (Brot). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 368 — Von Martens, 1899; Biol. Cent. Amer.: 462.

TYPE LOCALITY — Swamps in the woods bordering the Rio Grande, between Tampico and Mexico. This Rio Grande runs into the Lagoon of Meztitlán. The road from Tampico to Mexico City crosses the river between Zacualtipán and Atotonilco, Hidalgo (Von Martens, 1899).

DISTRIBUTION RECORDS — HIDALGO: known only from the type locality. Apparently this species is extinct. Attempts by FGT to locate populations in 2000 were unsuccessful.

Pachychilus (Oxymelania) suturalis Pilsbry & Hinkley, 1910

Pachychilus suturalis Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 529; pl. 24, figs. 16-29 — Pilsbry, 1956; Proc. Acad. Nat. Sci. Phila., 108: 37.

TYPE LOCALITY — Creek near Tampamolón, San Luís Potosí, Mexico. Holotype and 4 figured paratypes ANSP 99585.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: streams in the vicinity of Tampamolón; Coxcatlán; creek ca. 7 miles S of Huichihuayán; Tamazunchale (Pilsbry, 1956).

Pachychilus (Oxymelania) tristis Pilsbry & Hinkley, 1910

Pachychilus tristis Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 522; pl. 24, figs. 7-10 — Pilsbry, 1956; Proc. Acad. Nat. Sci. Phila., 108: 33.

TYPE LOCALITY — Tamasopo River at the natural bridge, near Verastagu, San Luís Potosí, Mexico. Holotype and 3 figured paratypes NSP 99566.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the immediate vicinity of the type locality.

Pachychilus (Oxymelania) vallesensis vallesensis Hinkley, 1907

Pachychilus vallesensis Hinkley, 1907; Nautilus, 21: 25; pl. 5, figs. 1-3, 5-7 — Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 528 — Pilsbry, 1956; Proc. Acad. Nat. Sci. Phila., 108: 37.

TYPE LOCALITY — Valles River, Valles, San Luís Potosí, Mexico. Holotype ANSP 96592.

DISTRIBUTION RECORDS — TAMAULIPAS, Rio Guayalejo system: Rio Frio, Gomez Farias; Rio Temesí, below the bridge at Magiscatzin (Pilsbry, 1956). SAN LUÍS POTOSÍ, Rio Panuco system: Rio Moctezuma at the ford south of Tampamolón; Rio Panuco, Pujal (Pilsbry & Hinkley, 1910).

Pachychilus (Oxymelania) vallesensis attenuatus Pilsbry & Hinkley, 1910

Pachychilus vallesensis Hinkley, 1907; Nautilus, 21: pl. 5, figs. 4, 8, 9.

Pachychilus vallesensis attenuatus Pilsbry & Hinkley, 1910; Proc. Acad. Nat. Sci. Phila., 61: 528.

TYPE LOCALITY — Chaimai Creek, about halfway between Valles and Pujal, San Luís Potosí, Mexico. Holotype and figured paratype ANSP 96592a.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: in addition to the type locality this subspecies is known from the Rio Casas Viejas, coming from the north of Valles and emptying into the Valles River some miles east of Mecos Falls (Pilsbry & Hinkley, 1910).

Subgenus Potamanax Pilsbry, 1892

Potamanax Pilsbry, 1892: 431 — Pilsbry, 1893b: 63.

Pachychilus (Oxymelania) Fischer & Crosse, in part. Morrison, 1954; Proc. U. S. Nat. Mus., 103: 365.

TYPE SPECIES — Potamanax rovirosai Pilsbry, 1892.

DISTRIBUTION — Three species are recognized from the Rio Usumacinta system of Guatemala and adjacent Mexico.

Pachychilus (Potamanax) pasionensis Pilsbry, 1956

Pachychilus pilsbryi (Von Martens). Goodrich & Van der Schalie, 1937; Misc. Pub. Univ. Mich. Mus. Zool., (34): 42-43.

Pachychilus pasionensis Pilsbry, 1956; Proc. Acad. Nat. Sci. Phila., 108: 34; pl. 4, figs. 4, 5.

TYPE LOCALITY — A small arroyo tributary to the Rio de la Pasión east of Sebol, Dept. Alta Verapaz, Guatemala. Holotype UMMZ 65510.

DISTRIBUTION RECORDS — GUATEMALA: known only from the Rio de la Pasión in the Dept. Petén and the Dept. Alta Verapaz (Goodrich & Van der Schalie, 1937).

Pachychilus (Potamanax) pilsbryi Von Martens, 1899.

P.[otamanax] rovirosai Pilsbry, 1893; Proc. Acad. Nat. Sci. Phila., 44: 431; pl. 14, figs. 8, 9 — Pilsbry, 1893; Nautilus, 7: 64: pl. 3, figs. 8, 9.

Pachychilus (Potamanax) rovirosai (Pilsbry). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 668; pl. 71, fig. 12.

Pachychilus pilsbryi Von Martens, 1899; Biol. Cent. Amer.: 463; pl. 46, fig. 8. (new name for P. [Potamanax] rovirosai Pilsbry, 1892, non Pachychilus glaphyrus var. rovirosai Pilsbry, 1892 — Von Martens, 1901; Biol. Cent. Amer.: 646, pl. 44, fig. 8 — Pilsbry, 1956; Proc. Acad. Nat. Sci. Phila., 108: 34; pl. 4, figs. 11, 12.

TYPE LOCALITY — Mountains of Poaná, Tabasco. Cotypes (2) ANSP 63386.

DISTRIBUTION RECORDS — TABASCO: Usumacinta River, Santa Gertruda (Von Martens, 1899); Santa Gertrudis, Usumacinta River (Von Martens, 1901).

REMARKS — The name pilsbryi was proposed by Von Martens, because he considered Potamanax not to be distinct from Pachychilus, subgen. Oxymelania. Thus, Potamanax rovirosai Pilsbry, 1892, p. 341 is a primary homonym of Pachychilus glaphyrus rovirosai Pilsbry, 1892, p. 153. However, Pilsbry (1893) compared Potamanax to the Cuban species Hemisinus brevis (Orbigny) (Thiaridae) and not to Pachychilus. The generic and familial affinities of this species remain to be resolved. Pilsbry did not address these questions in 1956 (Proc. Acad. Nat. Sci. Phila., 109).

Pachychilus (Potamanax) sargi (Crosse & Fischer, 1875)

Melania sargi Crosse & Fischer, 1875; Jour. de Conchyl., 23: 225, pl. 11, fig. 4 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melaniaceen): 335; pl. 34, figs. 12, 12a.

Pachychilus sargi (Crosse & Fischer). Fischer & Crosse, 1892; Miss. Sci. Mex., II: 338; pl. 51, figs. 6, 6a, 7 — Von Martens, 1899; Biol. Cent. Amer.: 463.

TYPE LOCALITY — Guatemala.

DISTRIBUTION RECORDS — GUATEMALA, Dept. Alta Verapaz: Cobán; Cahabón (Von Martens, 1899).

Family THIARIDAE Gill, 1871

Genus Aylacostoma Spix, 1827

Aylacostoma Spix, 1827; in Wagner, Testacea fluviatilia … Braziliam…, Munich: 15; pl. 8 — Morrison, 1954; Proc. U. S. Nat. Mus., 103: 375, 376.

TYPE SPECIES — Melania glabra Spix, 1827.

DISTRIBUTION — Central America south to southern Brazil.

TAXONOMY — The genus contains four subgenera, two of which occur in Central America (Morrison, 1954).

Subgenus Aylacostoma Spix, 1827

DISTRIBUTION — Guatemala, Colombia and Venezuela south to southeastern Brazil.

TAXONOMY — One species occurs in Guatemala. Numerous species are found in South America.

Aylacostoma rubiginosum (Morelet, 1849)

Melania rubiginosa Morelet, 1849; Testacea Noviss., I: 25.

Hemisinus rubiginosus (Morelet). H. & A. Adams; Gen. Recent Mollusca, I: 303 — Reeve, 1860: pl. 3, figs. 13, 13a — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab. (Melanidae): 394; pl. 41, fig. 1 — Hinkley, 1920; Nautilus, 34: 47.

Semisinus rubiginosus (Morelet). Fischer & Crosse, 1892: 318; pl. 50, figs. 11, 11a-d — Von Martens, 1899: 464.

Aylacostoma rubiginosum (Morelet). Morrison, 1954; Proc. U. S. Nat. Mus., 103: 377.

Melania petenensis Tristram, 1862; Proceedings of the Zoological Society: 441.

Hemisinus petenensis (Tristram). Brot, 1862; Materiaux fam. Melaniens, 2: 51.

Hemisinus zoster Brot, 1862; Materiaux fam. Melaniens, 2: 62.

TYPE LOCALITIES — Melania ruiginosa: Lago de Izabal, [Dept. Izabal], Guatemala. Melania petenensis: Lake of Petén, Guatemala. Hemisenus zoster: not given.

DISTRIBUTION — GUATEMALA, Dept. Izabal: Jocala, on the north shore of Lago de Izabal (Hinkley, 1920). Dept. Petén: Lake of Petén (Von Martens, 1899).

Subgenus Hemisinus Swainson, 1840

Hemisinus Swainson, 1840; Treatise on Malacology: 200, 341 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab., (Melanidae): 369 — Morrison, 1954; Proc. U. S. Nat. Mus., 103: 367.

Semisinus P. Fischer, 1885; Manuel de Conchyl., 701 — Fischer & Crosse, 1892: 313 — Von Martens, 1899: 464.

TYPE SPECIES — Melania lineolata Gray, 1828.

DISTRIBUTION — Jamaica, Central America south to Ecuador and to Peru.

Aylacostoma maculatum ( Lea, 1832)

Malania maculata Lea, 1832; Trans. Amer. Philos. Soc., 5: 194; pl. 19, fig. 75.

Semisinus maculatus (Lea) — Von Martens, 1901; Biol. Cent. Amer.: 646; pl. 46, fig. 7.

Melania osculatii Ant. Villa, 1855; Notizie interno al genera Melania, in Atti dell’ Accad. Fisico-Medio-statistica di Milano, 2: 8.

Hemisinus osculatii (Villa). Reeve, 1860: pl. 3, fig. 10 — Brot, 1874; in Martini & Chemnitz, Syst. Conch. Cab., (Melanidae): 379; pl. 8, figs. 8, 8, 8a-b.

TYPE LOCALITIES — Melania maculate: “Peru”. Melania osculatii: Quito, Ecuador.

DISTRIBUTION — COSTA RICA: confluence of the Rio Shei and the Rio Tararia (Von Martens, 1901). COLOMBIA. ECUADOR.

Genus Melanoides Olivier, 1804

Melanoides tuberculata (O. F. Müller, 1774)

DISTRIBUTION — Africa, Asia, Australia, the Pacific Islands. Introduced widely into Neotropical and Neotemparate regions. The species is spreading rapidly throughout Mexico and Central America, and by now it is assumed to be established in nearly all drainage systems in these countries.

TAXONOMY — Brandt (Archiv für Molluskenkunde, 105: 164) lists 37 synonyms for Melanoides tuberculatus. Melanoides are parthenogenetic uni-parental species, in which each individual is reproductively independent from all other individuals. Bi-parental species evolutionary concepts do not apply to such organisms. Melanoides turriculus (Lea, 1850) is a form that commonly is encountered in the Neotropical region. It is generally regarded as a synonym of M. tuberculatus.


Superfamily LITTORINOIDEA

Family ANNULARIIDAE Henderson & Bartsch, 1920

DISTRIBUTION — West Indies, south Florida, Mexico south to Panama, Colombia and Venezuela.

TAXONOMY — Numerous genera, subgenera and species.

REMARKS — Historically the classification of annulariids and their sister group, the Eur-Asian-Ethiopean Pomatiasidae, has been based on structure of the operculum and upon breathing devises associated with the aperture. Henderson & Bartsch (1920) provide a comprehensive classification of the Annulariidae based on these features. The opercula of many of the Mexico-Central American species were not known at that time. The classification presented below reflects new material I have examined. Solem (1961) adapted sub-generic terminology for the mainland species proposed by H. B. Baker (1928). Watters (2006, The Caribbean land snail family Annulariidae: a revision of higher taxa and catalog of the species: 1-577.) reviews the family and proposes a classification that differs from systems adapted by previous workers. He de-emphasisises the importance that other authors placed upon opercular and apertural features. His descriptions of generic groups are difficult to interpret because they do not adequately discriminate between some genera, even in different subfamilies. It is beyond the scope of this study to try to address the generic nomenclature proposed by Watters, because most of the names apply to West Indian taxa and have little bearing on the fauna of Mexico and Central America. This work follows the classification utilized by Solem, because it depicts phylogenetic and biogeographic relationships more clearly than later attempts to address these problems.

Watters provides a wealth of information on the species. He lists over 1500 species and subspecies names. This is the first compilation of species-group taxa since Henderson & Bartsch (1920), and it is a monumental achievement by itself. Fifteen species are known from Mexico and Central America.

Subfamily CHONDROPOMATINAE Henderson & Bartsch, 1920

Genus Chondropoma Pfeiffer, 1847

Chondropoma Pfeiffer, 1847; Zeit. Malak., 4: 109 — Henderson, 1914; Nautilus, 27: 138 — Henderson & Bartsch, 1920; Proc. U. S. Nat. Mus., 58 — Torre & Bartsch, 1942; Proc. U. S. Nat. Mus., 89: 349 — Bartsch, 1946; Bull. U. S. Nat. Mus., 192: 5 — Solem, 1961; Arch. Moll., 90: 204 — Watters, 2006: 25-28.

Gouldipoma Watters, 2006: 71.

TYPE SPECIES — Chondropoma: Cyclostoma sagra Orbigny, 1842; by original designation. Gouldipoma: Chondropoma callipeplum Solem, 1961a, by original designation.

DISTRIBUTION — Widely distributed in the West Indies and the circum-Caribbean region of the mainland from Florida and Mexico south tto Venezuela.

TAXONOMY — Many species and subspecies. Watters distinguishes Gouldipoma from Chondropoma on the basis of shell sculpture. He transfers Parachondria Dall, 1905 from the Subfamily Rhytodopominae to subgeneric status with Chondropoma. He changes the generic definitions of both and includes many disparate species. He synonymizes ten other subgenera and genera with Parachondria, further complicating a taxonomic dilemma. For purposes of this study I follow Solem (1961). The species tentatively are referred to the subgenus Chondropomium. Five species of Chondropoma are recognized from Mexico and Central America.

Subgenus Chondropomium Henderson & Bartsch, 1920.

Chondropomium Henderson & Bartsch, 1920; Proc. U. S. Nat. Mus., 58: 60 — Watters, 2006: 62-63.

TYPE SPECIES — Chondropoma weinlandi Pfeiffer, 1862.

DISTRIBUTION — Hispaniola, Jamaica, Mexico, Central America and Venezuela.

TAXONOMY — About 20 species are included in the subgenus.

Chondropoma (Chondropomium) callipeplum Solem, 1961

Chondropoma callipeplum Solem, 1961; Arch. Moll., 90: 207; pl. 11, fig. 21; pl. 12, fig. 24r (shell).

Gouldipoma callipeplum (Solem). Watters, 2006: 71, 183.

TYPE LOCALITY — Wani, Nicaragua. Holotype USNM 186093.

DISTRIBUTION — NICARAGUA: known only from the type locality.

Chondropoma (Chondropomium) cordovanum Pfeiffer, 1856.

Chondropoma cordovanum Pfeiffer, 1856; Proc. Zool. Soc. London: 91-92; pl. 25; figs. 18-19 (shell) — Fischer & Crosse, 1890: 207-210; pl. 41, figs. 6a-6c (shell) — Von Martens, 1890: 15, 17; Solem, 1961; Arch. Moll., 90: 204-205; pl. 11, figs. 15-17 (shell), pl. 12, figs. n, o (sculpture).

Chondropoma (Chondropomium) cordovanum Pfeiffer. H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 50.

Halotudora cordovana (Pfeiffer). Watters, 2006: 73, 216.

TYPE LOCALITY — Cordova [Cordoba], Veracruz, Mexico. Syntypes in the BMNH, ZMB and the MNHN.

DISTRIBUTION — VERACRUZ: Central Veracruz, near Cordoba.

Chondropoma (Chondropomium) gruneri (Pfeiffer, 1846)

Cyclostoma gruneri Pfeiffer, 1846; Zeit. Malak., 3: 47 — Pfeiffer, 1847: pl. 10; figs. 28-29 (shell).

Cistula gruneri (Pfeiffer). Gray, 1850; Cyclophoridae…: 59 — Pfeiffer, 1851; Zeit. Malak., 8: 170.

Chondropoma gruneri (Pfeiffer). Reeve, 1863; Conch. Icon., Chondropoma: 9, fig. 68 (shell — Von Martens, 1890: 18.

Ctenopoma gruneri (Pfeiffer). Fischer & Crosse, 1890: 188, 191.

Choanopoma (Choanopomops) gruneri (Pfeiffer). Solem, 1961; Arch. Moll., 90: 203.

Halotudora gruneri (Pfeiffer). Watters, 2006: 73, 283.

TYPE LOCALITY — Honduras; here restricted to Belize.

DISTRIBUTION — BELIZE: numerous specimen samples in the Florida Museum of Natural History.

Chondropoma (Chondropomium) küsteri (Pfeiffer, 1851)

Cyclostoma kusteri Pfeiffer. Pfeiffer, 1851; Proc. Zool. Soc. London: 249 — Pfeiffer, 1854: pl. 41, figs. 9-10 (shell).

Cistula küsteri Pfeiffer, 1852; Monogr. pneumo. vivent., 1: 265.

Chondropoma küsteri (Pfeiffer). Reeve, 1863; Conch. Icon., Chondropoma: pl. 11, fig. 87 (shell) — Von Martens, 1890: 18.

Ctenopoma küsteri (Pfeiffer). Fischer & Crosse, 1890: 194-186; pl. 42, figs. 7-7b.

Choanopoma (Choanopomops) küsteri (Pfeiffer). Solem, 1961; Arch. Moll., 90: 203-204.

Halotudora kuesteri (Pfeiffer). Watters, 2006: 73, 321.

TYPE LOCALITY — Honduras; here restricted to Belize.

DISTRIBUTION — BELIZE: numerous specimen samples in the Florida Museum of Natural History.

Chondropoma (Chondropomium) rubicundum (Morelet, 1849)

Cyclostoma rubicundum Morelet, 1849; Test Noviss., I: 22 — Pfeiffer, 1954; in Martini & Chemnitz Syst. Conch. Cab., Cyclostoma: 280; pl. 37, figs. 29, 30 (shell).

Chondropoma rubicundum (Morelet). Pfeiffer, 1851; Zeit. Malak., 8: 173. Reeve, 1863; Conch. Icon., Chondropoma: pl. 6, fig. 47 (shell) — Fischer & Crosse, 1890: 205-207; pl. 41, fig. 5 (shell) — Von Martens, 1890: 16-17 — Hinkley, 1920; Nautilus, 34: 42, 44, 52 — Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 31 — Bequaert, 1957: 212 — Solem, 1961; Arch. Moll., 90: 205-206; pl. 11, figs. 18-20; pl. 12, figs. 24p, 24q (shell).

Chondropoma (Chondropomium) rubicundum (Morelet). Henderson & Bartsch, 1920; Proc. U.S. Nat. Mus., 58: 60 — H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 50.

Gouldipoma cordovanum (Pfeiffer). Watters, 2006: 72, 448.

Cyclostoma acerbulum Morelet, 1851; Test. Noviss., II: 19.

Chondropoma acerbulum (Morelet). Fischer & Crosse, 190: 210-211; pl. 41, figs. 4-4d (shell) — Von Martens, 1890: 17.

Cistula subangulatum Von Martens, 1886; Sitzberg. Gesell. naturf. Freud. berlin, (10): 162.

Chondropoma subangulatum (Von Martens). Von Martens, 1890: 17; pl. 1, fig. 5 (shell).

TYPE LOCALITIES — Cyclostoma rubicundum: Petén et Vera Paz, Guatemala. Cyclostoma acerbulum: Vera paz, Guatemala. Chondropoma subangulatum: Teleman, Guatemala.

DISTRIBUTION — BELIZE: Cayo Dist. Succolz (Solem, 1961a). HONDURAS: extreme northwest of the country in the Dept. Cortes (FLMNH). GUATEMALA: numerous localities in the Depts. Petén, Alta Verapaz, Baja Verapaz (Goodrich & van der Schalie, 1937; Hinkley, 1920; Solem, 1961). CHIAPAS: Laguna Ocotal, 950 m alt. (Bequaert, 1957). TABASCO (Solem, 1961).

Subfamily ANNULARIINAE Henderson & Bartsch, 1920

Two genera occur in the Mexico-Central American region.

Genus Annularia Schumacher, 1817

Annularia Schumacher, 1817: 60, 196 — Henderson & Bartsch, 1920; Proc. U. S. Nat. Mus., 58: 71, 72 — Watters, 2006: 85-87 (in part).

TYPE SPECIES — Turbo lincina Linnaeus, 1758.

DISTRIBUTION — The Greater Antilles, Mexico.

TAXONOMY — A single species occurs in the study area. Numerous species occur in the West Indies.

Annularia sumichrasti Crosse & Fischer, 1874

Choanopoma sumichrasti Crosse & Fischer, 1877; Jour. de Conchyl., 22: 283 — Fischer & Crosse, 1890: 184-185; pl. 41, figs. 9, 9a (shell) — Solem, 1961; Arch. Moll., 90: 196-197 (in part) — Thompson, 1966; Nautilus, 80: 27; figs. 3, 4 (operculum).

Halotudora sumichrasti (Crosse & Fischer). Watters, 2006: 73.

TYPE LOCALITY — Isthmus of Tehuantepac, [Oaxaca], Mexico.

DISTRIBUTION — OAXACA: reported only from the type locality. Common in a small area on the south side of the Isthmus of Tehuantepec (FLMNH).

TAXONOMY — Solem (1961) confused this species with Choanopoma chiapensis Crosse & Fischer, 1877. Opercular differences indicate that they belong in different genera.

Genus Tudora Gray, 1850

Tudora Gray, 1850: 48 — Henderson & Bartsch, 1920; Proc. U. S. Nat. Mus., 58: 75, 76-77.

TYPE SPECIES — Cyclostoma similis Gray, 1843 [= Cyclostoma megacheilos Potiez & Michaud, 1838].

DISTRIBUTION — Jamaica, Caribbean coastal areas of the mainland; Dutch West Islands.

TAXONOMY — Henderson & Bartsch (1920) listed seven subgenera. H. B. Baker proposed the subgenus Tudorata to include mainland species found in Central America and South America.

Subgenus Tudorata H. B. Baker, 1924

Tudorata H. B. Baker, 1924; Occ. Pap. Mus. Zool. Univ. Mich., (152): 152: 44-45 — Solem, 1960; Arch. Moll., 90: 428.

Tudora Gray, 1850: Watters, 2006: 77.

TYPE SPECIES — Tudora muskusi H. B. Baker, 1924.

DISTRIBUTION — Coastal areas of the mainland from Venezuela north to Panama; Dutch West Indies.

TAXONOMY — Six species are recognized. One occurs in Central America.

Tudora (Tudorata) thomasi Solem, 1961

Tudora (Tudorata) thomasi Solem, 1961; Arch. Moll., 90: 208; pl. 11, fig. 23 (shell); pl. 12, fig. 24s (sculpture).

Gouldipoma thomasi (Solem). Watters, 2006: 72, 508.

TYPE LOCALITY — Natural Bridge of the Rio Puerto near the shore of Madden Lake, Canal Zone, Panama. Holotype FMNH 73390.

DISTRIBUTION — PANAMA: known only from the type locality.

Subfamily RHYTIDOPOMINAE Henderson & Bartsch, 1920

Genus Choanopoma Pfeiffer, 1847

Choanopoma Pfeiffer, 1847; Zeit. Malak., 3: 47 — H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 47-48.

TYPE SPECIES — Turbo lincina Linnaeus, 1758.

DISTRIBUTION — West Indies, Caribbean coastal areas of the mainland.

TAXONOMY — Much controversy centers about the use of the name Choanopoma. Henderson & Bartsch (1920) and Waters (2006) treat Choanopoma as a synonym of Annularia. H. B. Baker (1928) recognizes Choanopoma as a valid genus. Solem (1961) follows H. B. Baker but points out the unstable taxonomy surrounding the name Choanopoma. A single subgenus, Choanopomops, is recognized in Mexico and Central America.

Subgenus Choanopomops H. B. Baker, 1928

Choanopomops H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 48 — Solem, 1961; Arch. Moll., 90: 194 — Watters, 2006: 58 (in part).

Halotudora Watters, 2006: 73.

TYPE SPECIES — Chondropomops: Cyclostoma largillieti Pfeiffer, 1846. Halotudora: Cyclostoma radiosum Morelet, 1849.

DISTRIBUTION — Caribbean coastal areas of the mainland, Jamaica and Cuba (H. B. Baker, 1928).

TAXONOMY — Nine species are recognized in Mexico and Central America. Additional species occur in northern South America and Jamaica.

Choanopoma (Choanopomops) andrewsae (Ancey, 1886)

Cyclostoma andrewsae Ancey, 1886; Ann. de malac., 2: 251-252.

Colobostylus andrewsae (Ancey). Fischer & Crosse, 1890: 218.

Choanopoma andrewsae (Ancey). Von Martens, 1890: 16; pl. 1, fig. 4 (shell) — Richards, 1937; Proc. Amer. Philos. Soc., 77: 256 — Richards, 1938; Proc. Amer. Philos. Soc., 79: 176, 178 — Thompson, 1967; Bull. Fla. St. Mus., 11: 222-227, figs. 6a, b (operculum).

Chondropoma andrewsae (Ancey) — Henderson & Bartsch, 1920; Proc. U. S. Nat. Mus., 58: 60.

Choanopoma (Choanopomops) andrewsae andrewsae (Ancey). Solem, 1961; Arch. Moll., 90: 198; pl. 10, fig. 10 (shell); pl. 12, fig. 24I (sculpture).

Choanopoma cozumelense Richards, 1937; Proc. Amer. Philos. Soc., 77: 256; pl. 4, fig. 3 (shell) — Solem, 1961; Arch. Moll., 90: 198; pl. 10, fig. 7 (shell); pl. 12, fig. 24g(sculpture).

Choanopoma andrewsae roatanense Richards, 1938; Proc. Amer. Philos. Soc., 79: 174; pl. 3, figs. 1, 7 (shell) — Solem, 1961; Arch. Moll., 90: 200; pl. 10, fig. 10 (shell); pl. 12, fig. 24I (sculpture).

Annularia (Choanopomops) cozumelensis (Richards). Rehder, 1966; Proc. Biol. Soc. Wash., 79: 279.

Tudorisca andrewsae andrewsae (Ancey). Watters, 2006: 79, 140.

Tudorisca andrewsae roatanense (Richards). Watters, 2006: 79, 140.

Tudorisca cozumelense (Richards). Watters, 2006: 79, 218.

TYPE LOCALITY — Cyclostoma andrewsae: Utila Island, Honduras. Choanopoma cozumelense: San Gerbacio, Cozumel Island, Quintana Roo, Mexico; holotype ANSP 167749. Choanopoma andrewsae roatanense: West End, Roatán Island, Honduras; holotype ANSP 170018.

DISTRIBUTION — HONDURAS: Roatán Island; Utila Island. CAMPECHE: 5.1 mi. NNW of Dzilbachén; 3.6 mi. S of Hopelchén; 3.4 mi. S of Cayál. QUINTANA ROO: Tulúm (Rehder, 1966); 4.0 mi. E of Xpujil, Campeche; 7.1 mi. NNW Xiatil; 2.3 mi. SSE Xiatil; San Sebastian, Cozumel Island (Thompson, 1967c). YUCATAN: 0.8 mi. NE Becanchén; 10.0 mi. NE Becanchén; Chichen Itza (Thompson, 1967c).

Choanopoma (Choanopomops) chiapasense Crosse & Fischer, 1877

Choanopoma chiapasense Crosse & Fischer, 1877; Jour. de Conchyl., 25: 362-363 — Fischer & Crosse, 1890: 182-184; pl. 41, figs. 8, 8a (shell) — Bequaert & Clench, 1931; Occ. Pap. Boston Soc. Nat. Hist., 5: 426 — Bequaert & Clench, 1933; Pub. Carnegie Inst. Wash., (431): 542 — Bequaert, 1957: 225.

Tudora (Tudorisca) chiapensis [sic] (Crosse & Fischer, 1877). Henderson & Bartsch, 1920; Proc. U. S. Nat. Mus., 58: 76.

Choanopoma (Choanopomops) sumichrasti var. chiapasense Crosse & Fischer. Solem, 1961; Arch. Moll., 90: 197; pl. 10, fig. 4 (shell); pl. 12, fig. 24d (sculpture).

Choanopoma (Choanopomops) chiapensis [sic] Crosse & Fischer. Thompson, 1966; Nautilus, 80: 27; fig. 4 (operculum).

Halotudora chiapasense (Crosse & Fischer). Watters, 2006: 73, 201.

TYPE LOCALITY — Chiapas.

DISTRIBUTION — CHIAPAS: Santo Domingo; Chivela; Lagunas (Solem, 1961a); 8 km. E of Chiapa de Corzo, 3100 ft. alt; 14.9 mi. E of Chiapa de Corzo, 4400 ft. alt.; 8 mi. km of Tuxtla Gutierrez, 380 ft. alt. (Thompson, 1966).

Choanopoma (Choanopomops) gaigei Bequaert & Clench, 1931

Choanopoma gaigei Bequaert & Clench, 1931; Occ. Pap. Boston Soc. Nat. Hist., 5: 425-426 — Bequeart & Clench, 1933; Pub. Carnegie Inst. Wash., (431): 540-542; text-fig. 26; pl. 68, figs. 8-11 (shell) — Bequaert & Clench, 1936; Pub. Carnegie Inst. Wash., (457): 72 — Goodrich & van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 12, 15, 22, 32 — Harry, 1950; Occ. Pap. Mus. Zool. Univ. Mich., (524): 26-28 — Solem, 1961; Arch. Moll., 90: 197, pl. 10, fig. 5 (shell); pl. 12, fig. 24e (sculpture) — Branson & McCoy, 1963; Nautilus, 76: 104 — Thompson, 1966; Nautilus, 80: 27 — Thompson, 1967; Bull. Fla. St. Mus., 11: 225, 227.

Choanopoma gagei [sic] Bequaert & Clench — Richards, 1937; Proc. Amer. Philos. Soc., 77: 257.

Halotudora gaigei (Bequaert & Clench). Watters, 2006: 73, 269.

TYPE LOCALITY — Chichin Itza, Yucatan. Holotype UMMZ 49190.

DISTRIBUTION — GUATEMALA, Dept. Petén: 1 mi. NW of Paso Caballo; 4 mi. N of Paso Caballo (Goodrich & van der Schalie, 1937). CAMPECHE: numerous localities (Thompson, 1967c). QUINTANA ROO: 4.0 mi. E of Xpujil (Campeche); 7.1 mi. NNE of Polyuc; 2.3 mi. SSE Polyuc (Thompson, 1966). YUCATAN: vicinity of Chichin Itza (Bequaert & Clench, 1931, 1933, 1936; Harry, 1950); 0.8 mi. NE Becanchen (Thompson, 1966).

Choanopoma (Choanopomops) largillierti (Pfeiffer, 1846)

Cyclostoma largillierti Pfeiffer, 1846; Zeit. Malak., 3: 46 — Pfeiffer, 1847; Zeit. Malak., 4: pl. 14, figs. 26, 27 (shell).

Cyclostoma grataloupi Pfieffer, 1853 [for 1851]; Proc. Zool. Soc. Wash.: 246, 247 — Pfeiffer, 1854; pl. 40, figs. 28, 29 (shell).

Ctenopoma largillierti (Pfeiffer). Fischer & Crosse, 1890: 196-197; pl. 42, figs. 10-10b (shell).

Ctenopoma grateloupi (Pfeiffer). Fischer & Crosse, 1890: 199-200; pl. 42, figs. 8-8b (shell).

Chondropoma largillierti (Pfeiffer). Von Martens, 1890: 19.

Licina (Choanopomops) largillierti (Pfeiffer). H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 46-49, pl. 2, fig. 35.

Licina (Choanopomops) grateloupi (Pfeiffer). H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 48-49; pl. 2, fig. 36 (radula).

Choanopoma largillierti (Pfeiffer). Bequaert & Clench, 1933; Pub. Carnegie Inst. Wash., (431): 540 — Richards, 1937; Proc. Amer. Philos. Soc., 77: 257 — Bequaert & Clench, 1938; Pub. Carnegie Inst. Wash., (491): 259 — Harry, 1950; Occ. Pap. Mus. Zool. Univ. Mich., (524): 26-28; fig. 3 (shell) — Branson & McCoy, 1963; Nautilus, 76: 104-105 — Thompson, 1966; Nautilus, 80: 27 — Thompson, 1967; Bull. Fla. St. Museum, 11: 224-225 — Watters, 2006: 58, 326.

Choanopoma (Choanopomops) largillierti (Pfeiffer). Bequaert & Clench, 1936; Pub. Carnegie Inst. Wash., (457): 71-72 — Haas & Solem, 1960; Nautilus, 73: 130 — Solem, 1961; Arch. Moll., 90: 200-202; pl. 10, figs. 11, 12 (shell); pl. 12, figs. 24j, 24k (sculpture).

Choanopomops grateloupi (Pfeiffer). Watters, 2006: 58, 279.

Choanopomops largillierti (Pfeiffer). Watters, 2006: 58, 326.

TYPE LOCALITY — Cyclostoma largillierti: Yucatán, Mexico. Cyclostoma grateloupi: Yucatán, Mexico.

DISTRIBUTION — CAMPECHE: numerous localities (Thompson, 1967c). YUCATAN: numerous localities (Bequaert & Clench, 1938; Branson & McCoy, 1963; Thompson, 1966, 1967). QUINTANA ROO: Tulúm (Rehder, 1966); numerous localities (Thompson, 1966). BELIZE: Chetumal (Solem, 1961).

Choanopoma (Choanopomops) martensianum (Pilsbry, 1900)

Chondropoma martensianum Pilsbry, 1900; Nautilus, 13: 140 — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 780; pl. 52, figs. 4, 4a (shell) — Thompson, 1957; Nautilus, 70: 100 — Solem, 1961; Arch. Moll., 90: 197-198; pl. 10, fig. 6 (shell); pl. 12, fig. 24f (sculpture).

TYPE LOCALITY — Mountains of Poana, Tabasco, Mexico. Holotype ANSP 63417.

DISTRIBUTION — TABASCO: known only from the type locality and from near-by areas near Teapa (Thompson, 1957).

Choanopoma (Choanopomops) osberti (Tristram, 1861)

Adamsilla osberti Tristram, 1861; Proc. Zool. Soc. London: 232 — Fischer & Crosse, 1890: 178-179; pl. 42, figs. 13-13b (shell).

Licina osberti (Tristram). H. B. Baker, 1928; Occ. Pap. Mus. Zool. Univ. Mich., (193): 48.

Choanopoma osberti (Tristram). Von Martens, 1890: 16 — Solem, 1961; Arch. Moll., 90: 195-197; pl. 10, fig. 2 (shell); pl. 12, fig. 24b (sculpture).

Annularia rigidula (Morelet). Haas, 1949; Nautilus, 62: 136.

Parachondrops osberti (Tristram). Watters, 2006: 47, 386-387.

TYPE LOCALITY — Guatemala.

DISTRIBUTION — GUATEMALA, Dept. Sacatepequez: Sacatepequez (Solem, 1961).

Choanopoma (Choanopomops) radiosum (Morelet, 1849)

Cyclostoma radiosum Morelet, 1849; Test Noviss., I: 22.

Cistula radiosa.(Morelet). Pfeiffer, 1851; Zeit. Malak., 8: 169 — Crosse & Fischer, 1883: 103 — Hinkley, 1920; Nautilus, 34: 44.

Chondropoma radiosum (Morelet). Reeve, 1963; Conch. Icon., Chonropoma: pl. 9, fig. 69 (shell). Von Martens, 1890: 18 — Pilsbry, 1900; Nautilus, 13: 140.

Ctenopoma sargi Crosse & Fischer, 1883; Jour. de Conchyl., 31: 103.

Ctenopoma radiosum (Morelet). Fischer & Crosse, 1890: 188-191; pl. 42, figs. 1-1b (shell).

Ctenopoma sargi Crosse & Fischer. Fischer & Crosse, 1890: 191-194; pl. 42, figs. 4-4b (shell).

Choanopoma radiosum (Morelet). Goodrich & van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 20. 31 — Thompson, 1966; Nautilus, 80: 28.

Licina radiosa (Morelet). Basch, 1959; Occ. Pap. Mus. Zool. Univ. Mich., (612): 7.

Choanopoma (Colobostylus) radiosum (Morelet). Haas & Solem, 1960; Nautilus, 73: 130; pl. 13, figs. 5-7.

Choanopoma (Choanopomops) radiosum (Morelet). Solem, 1961; Arch. Moll., 90: 197-198; 202-203; pl. 11, figs. 13, 14 (shell); pl. 12, fig. 24l (sculpture).

Chondropoma sargi (Crosse & Fischer). Von Martens, 1890: 18.

Halotudora radiosua (Morelet). Watters, 2006: 73, 430.

TYPE LOCALITY — Cyclostoma radiosum: Petén, Guatemala. Cistula sargi: San Miguel de Tucuru, Dept. Alta Verapaz, Guatemala (Solem, 1961).

DISTRIBUTION — BELIZE: Punta Gorda; Gales Point; Bienque Viejo; Augustino (Solem, 1961). GUATEMALA: widely distributed in the Depts. Petén, Alta Verapaz, Izabal (Solem, 1961).

Choanopoma (Choanopomops) rigidulum (Morelet, 1851)

Cyclostoma rigidulum Morelet, 1851; Test. Noviss., II: 18.

Adamsiella rigidula (Morelet). Fischer & Crosse, 1890: 176-178; pl. 42, figs. 12-12b (shell).

Choanopoma rigidulum (Morelet). Von Martens, 1890: 16; pl. 1, fig. 3 (shell).

Choanopoma (Choanopoma) rigidulum (Morelet). Haas & Solem, 1960; Nautilus, 73: 130.

Choanopoma (Choanopomops) rigidulum (Morelet). Solem. 1961; Arch. Moll., 90: 195-196; pl. 10, fig. 1 (shell); pl. 12, fig. 24a (sculpture).

Licina (Choanopomops) rigidulum (Morelet). H. B. Baker, 1928; Occ. Pap. Mus. Zol. Univ. Mich., (193): 48-49.

Parachondrops rigidulus (Morelet). Watters, 2006: 47, 442.

TYPE LOCALITY — San Luís, Dept. Petén, Guatemala [Watters, 2006]. Holotype BMNH 93.2.4.704-5.

DISTRIBUTION — GUATEMALA: reported only from the type locality. BELIZE, Cayo District: Rio Frio Cave, 2 mi. from Augustine (Haas & Solem, 1960).

Choanopoma (Choanopomops) terecostatum Thompson, 1966

Choanopoma terecostatum Thompson, 1966; Nautilus, 80: 24-28; figs. 1, 5 (operculum); figs. 7 (shell).

Halotudora terecostata (Thompson). Watters, 1906: 73, 506.

TYPE LOCALITY — Limestone hillside 15.8 miles [25 km] northwest of Ocozocoautla, Chiapas, 2700 ft. [830 m] alt. Holotype UMMZ 216554.

DISTRIBUTION — CHIAPAS: known only from the type locality.

Annulariidae of doubtful occurrence in Mexico and Central America

Chondropoma turritum Pfeiffer, 1853

Chondropoma turritum Pfeiffer, 1853 [for 1851]; Proc. Zool. Soc. London: 248 — Pfeiffer, 1854: 310; pl. 41, figs. 1-2 (shell) — Von Martens, 1890: 19-20 — Solem, 1962; Arch. Moll., 90: 207; pl. 11, fig. 22 (shell).

Gouldipoma turritum­ (Pfeiffer). Watters, 2006: 72, 527.

TYPE LOCALITY — Honduras.

DISTRIBUTION. — Unknown.

REMARKS — Chondropoma turritum is very similar to Chondropoma canescens (Pfeiffer, 1852) from Cuba. It may be a West Indian species incorrectly attributed to Honduras.

Cyclostoma vespertitum Morelet, 1851

Cyclostoma vespertitum Morelet, 1851; Test. Noviss., II: 19.

Chondropoma vespertitum (Morelet). Fischer & Crosse, 1890: 211-212; pl. 41, figs. 7, 7a (shell) — Von Martens, 1890: 19, 610 — Torre & Bartsch, 1938; Proc. U. S. Nat. Mus., 85: 341-342 — Solem, 1961; Arch. Moll., 90: 209 — Watters, 2006: 534.

REMARKS — This species was erroniusly recorded by Morelet as coming from Palenque, Chiapas, Mexico. Torre & Bartsch identify it as a species found on the Isle of Pines, Cuba.

Cistula pleurophorum (Pfeiffer, 1852)

Cistula pleurophorum Pfeiffer, 1853 [for 1851]; Proc. Zool. Soc. London: 169 — Fischer & Crosse, 1890: 218.

Chondropoma pleurophorum (Pfeiffer). Von Martens, 1890: 16.

Choanopoma (Choanopomops) pleurophorum (Pfeiffer). Solem, 1961; Arch. Moll., 90: 198-199; pl. 10, fig. 9 (shell).

TYPE LOCALITY — Honduras.

DISTRIBUTION — Unknown. This species has not been found since its original description. It may be a West Indian species (see Solem, 1961).


Superfamily RISSOOIDEA

Family HYDROBIIDAE Troschel, 1857

This is a very large cosmopolitan family of fresh and brackish water snails. The family includes several hundred genera. One hundred and nine (109) species occur in the study area.

Subfamily COCHLIOPINAE Tryon, 1866

Cochliopinae Tryon, 1866 — Taylor, 1966 — Hershler & Thompson, 1992.

Littoridininae Thiele, 1928 — Taylor, 1966 (in part).

Mexithauminae Taylor, 1966 (in part).

Paludiscalinae Taylor, 1966 (in part).

Semiscalinae Giusti & Pezolli, 1980.

TYPE GENUS — Cochliopa Stimpson, 1865.

DISTRIBUTION — North America, throughout South America, the West Indies, central Africa and the Mediterranean region.

TAXONOMY — About thirty-five genera are recognized.

Genus Aroapyrgus Baker, 1931

Aroa Baker, 1930; Occ. Pap. Mus. Zool. Univ. Mich., (210): 33. (Type species by original designation: Potamopyrgus ernesti vivens Baker, 1930.) Non Walker, 1855, Lepidoptera.

Aroapyrgus, Baker, 1931; Nautilus, 44: 124. Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 24. (Replacement name for Aroa H. B. Baker, 1930.)

Sioliella Haas, 1949; Anal. Inst. Biol. Mex.,20: 307 (type species by original designation: Sioliella effusa Haas, 1949 (subjective synonym).

DISTRIBUTION — North and South America from San Luís Potosí, México, south to Colombia and east to Pará State, Brazil.

TAXONOMY — Twenty-nine species are recognized (Hershler & Thompson, 1992). Nineteen occur in the study area.

Aroapyrgus alleei Morrison, 1946

Aroapyrgus alleei Morrison, 1946; Smiths. Misc. Coll., 106: 14; pl. 2, fig. 4; pl. 3, fig. 3 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 26.

TYPE LOCALITY — Allee Stream, Barrow Colorado Island, Gutun Lake, Canal Zone, Panama. Holotype USNM 542142.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Aroapyrgus chagresensis Morrison, 1946.

Aroapyrgus chagresensis Morrison, 1946; Smiths. Misc. Coll., 106: 14-15; pl. 2, fig. 3; pl. 3, fig. 4 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 26.

TYPE LOCALITY — Río Chagres, Gatuncilla, Panama. Holotype USNM 542144.

DISTRIBUTION RECORDS — PANAMA: recorded only from the Río Chagres at the type locality and Madronal.

Aroapyrgus cisterninus (Walker, 1919)

Amnicola cisternina Walker, 1919; Occ. Pap. Mus. Zool. Univ. Mich., (73): 1-2; pl. 1, fig. 1.

Aroapyrgus cisternina (Walker). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 26

TYPE LOCALITY — Reservoir north of Guatemala City, Dept. Guatemala, Guatemala. Holotype UMMZ 47161.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Aroapyrgus clenchi (Goodrich & Van der Schalie, 1937)

Somatogyrus clenchi Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 37; pl. 1, fig. 6.

Aroapyrgus clenchi (Goodrich & Van der Schalie). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 26.

TYPE LOCALITY — Río de La Pasión, Sayaxche, Dept. Petén, Guatemala. Holotype in the UMMZ.

DISTRIBUTION RECORDS — GUATEMALA: Dept. Petén: Río de La Pasión and Arroyo Subín. TABASCO: Río Usumacinta and tributaries.

Aroapyrgus conchensensis (Walker, 1919)

Amnicola conchensensis Walker, 1919; Occ. Pap. Mus. Zool. Univ. Mich., (73): 3-4; pl. 1, figs. 4-5.

Aroapyrgus conchenensis (Walker). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 27.

TYPE LOCALITY — “Conchens River”, Guatemala. UMMZ 38508.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Aroapygus costaricenis (Mörch, 1860)

Hydrobia costaricensis Mörch, 1860: 67 — Frauenfeld, 1864: 594.

Amnicola costaricensis (Mörch). Von Martens, 1899; Biol. Cent. Amer.: 435; pl. 22, fig. 6; 644.

Aroapyrgus costaricensis (Mörch). Thompson, 1968; Fla. Hydrob.: 150 — Malek, E. A., R. Brenes & G. Rojas, 1975; Jour. parasit., 61: 355-359 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 27.

TYPE LOCALITY — Río Torres, San José Province, Costa Rica. Location of syntypes unknown.

DISTRIBUTION RECORDS — COSTA RICA: Streams at intermediate elevations of San José Prov., Cartago Prov., and Puntarenas Prov.

Aroapyrgus guatemalensis (Fischer & Crosse, 1891)

Amnicola guatemalensis Fischer & Crosse, 1891; Miss. Sci. Mex., II: 264; pl. 50, figs. 5-5b.

Amnicola hyalina (Fischer & Crosse) (in part). Von Martens, 1899; Biol. Cent. Amer.: 432.

Aroapyrgus guatemalensis (Fischer & Crosse). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 27.

TYPE LOCALITY — Lago de Amatitlán, Dept. Guatemala, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality. A record from Lago de Catemaco, VERACRUZ, México (Baker, 1922) requires confirmation.

Aroapyrgus hinkleyi (Walker, 1919)

Amnicola hinkleyi Walker, 1919; Occ. Pap. Mus. Zool. Univ. Mich., (73): 4; pl. 1, fig. 6.

Aroapyrgus hinkleyi (Walker). Thompson, 1968; Fla. Hydrob.: 27 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 27.

TYPE LOCALITY — Reservoir north of Guatemala City, Dept. Guatemala, Guatemala. Holotype UMMZ 47162.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Aroapyrgus joseana Morrison, 1946.

Aroapyrgus joséana Morrison, 1946; Smiths. Misc. Coll., 106: 15-16; pl. 2, fig. 6; pl. 3, fig. 8 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 27.

TYPE LOCALITY — A northern tributary of the Río Mata Puerco Estuary, San José Island, Archipelago de Las Perlas, Panama. Holotype USNM 542147.

DISTRIBUTION RECORDS — PANAMA: known only from small streams on San José Island.

Aroapyrgus mexicanus (Pilsbry, 1910)

Somatogyrus mexicanus Pilsbry, 1910; Nautilus, 23: 98-99; pl. 9, fig. 3.

Aroapyrgus mexicanus (Pislbry). Hershler & Thompson, 1992; Malacological Rev., Suppl. 5: 28.

TYPE LOCALITY — Río Coy, on the road to Tampamolán, San Luís Potosí, México. Lectotype ANSP 99023 (Baker, 1964).

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Aroapyrgus orizabensis (Crosse & Fischer, 1891)

Amnicola orizabensis Crosse & Fischer, 1891; Jour. de Conchyl., 39: 24 — Fischer & Crosse, 1891; Miss. Sci. Mex., II: 263; pl. 50, figs. 4-4b — Von Martens, 1899; Biol. Cent. Amer.: 432.

Aroapyrgus orizabensis (Crosse & Fischer). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 28.

TYPE LOCALITY — Near Orizaba, Veracruz State, México.

DISTRIBUTION RECORDS — VERACRUZ: known only from the immediate vicinity of the type locality.

Aroapyrgus panamensis (Tryon, 1863)

Amnicola panamensis Tryon, 1963; Proc. Acad. Nat. Sci. Phila., 15: 146; pl. 1, fig. 6 — Von Martens, 1899; Biol. Cent. Amer.: 432 — Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 781; pl. 52, fig. 11.

Aroapyrgus panamensis (Tryon). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 27.

TYPE LOCALITY — Panama. Holotype ANSP 58067.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality. A records for Javalí, Dept. Chontales, Nicaragua (Tate, 1870: 153) refers to A. tryoni.

Aroapyrgus panzosensis (Walker, 1919)

Amnicola panzosensis Walker, 1919; Occ. Pap. Mus. Zool. Univ. Mich., (73): 3; pl. 1, figs. 2-3.

Aroapyrgus panzosensis (Walker). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 28.

TYPE LOCALITY — Panzos, Río Polochíc Valley, Dept. Alta Verapaz, Guatemala. Holotype UMMZ 37389.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Aroapyrgus pasionensis (Goodrich & Van der Schalie, 1937)

Amnicola pasionensis Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 36; pl. 1, fig. 4.

Aroapyrgus pasionensis (Goodrich & Van der Schalie). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 28.

TYPE LOCALITY — Arroyo Subín, a tributary of the Río de La Pasión, about 3 km above Santa Teresa, Dept. Petén, Guatemala. Holotype UMMZ.

DISTRIBUTION RECORDS — GUATEMALA: known from the Río de la Pasión and tributaries, Dept. Petén, and from the Río Usumacinta and tributaries, TABASCO, México.

Aroapyrgus petenensis (Morelet, 1851)

Paludina petenensis Morelet, 1851; Test. Noviss., II: 21.

Amnicola petenensis (Morelet). Frauenfeld, 1864: 635. Fischer & Crosse, 1891; Miss. Sci. Mex., II: 262; pl. 50, figs. 3-3b — Von Martens, 1899; Biol. Cent. Amer.: 430-431 — Goodrich, and Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 36.

Aroapyrgus petenensis (Morelet). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 28.

TYPE LOCALITY — Lago de Itza, Dept. Petén, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known from various lakes in the Dept. Petén.

Aroapyrgus rhegoides (Morelet, 1851)

Paludina rhegoides Morelet, 1851; Test. Noviss., II: 22.

Amnicola rhegoides (Morelet). Von Martens, 1899; Biol. Cent. Amer.: 432; pl. 22, fig. 4.

Aroapyrgus rhegoides (Morelet). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 28.

TYPE LOCALITY — Lago de Coatepeque, Dept. Santa Ana, El Salvador.

DISTRIBUTION RECORDS — El Salvador: known only from the type locality.

Aroapyrgus stolli (Von Martens, 1901)

Amnicola stolli Von Martens, 1901; Biol. Cent. Amer.: 645; pl. 46, fig. 14.

Aroapyrgus stolli (Von Martens). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 28.

TYPE LOCALITY — Lago de Atitlán, Dept. Sololá, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Aroapyrgus subangulatus (Von Martens, 1899)

Amnicola subangulata Von Martens, 1899; Biol. Cent. Amer.: 435; pl. 22, fig. 5.

Aroapyrgus subangulata (Von Martens). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 28.

TYPE LOCALITY — Río Torres, in the environs of San José, San José Prov., Costa Rica; 1100 m alt.

DISTRIBUTION RECORDS — COSTA RICA, Limón Prov.: recorded from the type locality and from a small stream between the Río Madre de Dios and the Río Hondo, 80 m alt.

Aroapyrgus tryoni (Pilsbry, 1904)

Amnicola tryoni Pilsbry, 1904; Proc. Acad. Nat. Sci. Phila., 55: 781; pl. 52, fig. 10 — Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 9.

Aroapyrgus tryoni (Pilsbry). Thompson, 1968; Fla. Hydrob.: 150 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 29.

TYPE LOCALITY — Roots of plants in a swampy pool near Javalí, Dept. Chontales, Nicaragua. Holotype ANSP 58066a.

DISTRIBUTION RECORDS — NICARAGUA: known only from the type locality. COSTA RICA: Río Reventazón, Juan Vinales, 800 m; 4 mi SW of Cartago, 1200 m (Pilsbry, 1920). A record from Tampico, México almost certainly is in error (Hinkley, 1907; Nautilus, 21: 79).

Genus Coahuilix Taylor, 1966

Coahuilix Taylor, 1966; Veliger, 9: 180 — Hershler, 1985; Malacologia, 26: 53-54 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 31.

TYPE SPECIES — By original designation: Coahuilix hubbsi Taylor, 1966.

DISTRIBUTION — Cuatro Ciénegas Basin, Coahuila, México.

TAXONOMY — Two species (Hershler & Thompson, 1992).

Coahuilix hubbsi Taylor, 1966

Coahuilix hubbsi Taylor, 1966; Veliger, 9: 180-181; figs. 8-13 — Hershler, 1985; Malacologia, 26: 54-57; figs. 15A-E, 16, 17 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 31; figs. 17-18.

TYPE LOCALITY — Pozo de Becerra, Cuatro Ciénegas Basin, Coahuila, México. Holotype UMMZ 220180.

DISTRIBUTION RECORDS — Endemic to springs in the Cuatro Ciénegas Basin, Coahuila, México.

Coahuilix landyei Hershler, 1985

Coahuilix landyei Hershler, 1985; Malacologia, 26: 57-58; figs. 15F, G, I, J, K — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 33.

TYPE LOCALITY — A small spring 1.12 km south of the north tip of the Sierra de San Marcos, Cuatro Ciénegas Basin, Coahuila, México. Holotype ANSP A9894n.

DISTRIBUTION RECORDS — COAHUILA: endemic to springs in the Cuatro Ciénegas Basin.

Genus Cochliopa Stimpson, 1865

Cochliopa Stimpson, 1865; Amer. Jour. Conch., 1: 52. Morrison, 1946; Smiths. Misc. Coll., 106: 27 — Taylor, 1966; Veliger, 9: 175 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 33.

TYPE SPECIES — Amnicola rowelli Tryon, 1863, by original designation.

DISTRIBUTION — CENTRAL AMERICA: Pacific coastal streams of Panama.

HABITAT — Brackish water and freshwater just above the brackish zone.

TAXONOMY — Four species are recognized.

Cochliopa diazensis Morrison, 1946

Cochliopa diazensis Morrison, 1946; Smiths. Misc. Coll., 106: 27-28; pl. 2, fig. 15; pl. 3, fig. 18 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 33-34.

TYPE LOCALITY — Río Juan Diaz, just below Las Sabanas Road bridge east of Panama City, Panama Province, Panama. USNM 542170.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Cochliopa joséana Morrison, 1946.

Cochiopa joséana Morrison, 1946; Smiths. Misc. Coll., 106: 28-29; pl. 2, fig. 18; pl. 3, fig. 19 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 32-33; fig. 20a, c, d; fig. 21.

TYPE LOCALITY — Río Mata Puerco, which opens into the Ensenada de Bodega, southwest part of Isla San José, Archipelago de Las Perlas, Panama. Holotype USNM 542173.

DISTRIBUTION RECORDS — PANAMA: known only from small streams on Isla San José.

Cochliopa perforata Thompson & Hershler, 1991

Cochliopa perforata Thompson & Hershler, 1991; Proc. Biol. Soc. Wash., 104: 671-672; fig. 2 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 35; fig. 20b.

TYPE LOCALITY — A small stream 1 km northwest of Golfito Bay, Puntarenas Prov., Costa Rica. Holotype FLMNH 175911.

DISTRIBUTION RECORDS — COSTA RICA, Puntarenas Prov.: known only from small streams near Golfito.

Cochliopa rowelli (Tryon, 1863)

Amnicola rowelli Tryon, 1863; Proc. Acad. Nat. Sci. Phila., 15: 147; pl. 1, figs. 8-9.

Cochliopa rowelli (Tryon). Stimpson, 1865; Amer. Jour. Conch., 1: 52 — Pilsbry, 1905; Nautilus, 19: 91-92 — Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 198 — Morrison, 1946; Smiths. Misc. Coll., 106: 27; pl. 3, fig. 17 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 34.

TYPE LOCALITY — Restricted to Río Matasnillo, Panama City, Panama (Morrison, 1946; Smiths. Misc. Coll., 106: 27). Lectotype ANSP 58282a (Baker, 1946).

DISTRIBUTION RECORDS — PANAMA: known only from the type locality, where it is now extinct.

Genus Cochliopina Morrison, 1946

Cochliopina Morrison, 1946; Smiths. Misc. Coll., 106: 18-19 — Taylor, 1966; Veliger, 9: 176 — Hershler, 1985; Malacologia, 26: 65 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 36.

TYPE SPECIES — By original designation: Cochliopa riograndensis Pilsbry and Ferriss, 1906.

DISTRIBUTION — North America, Central America and South America from Texas south to the Río Santiago, Ecuador.

TAXONOMY — Nineteen species.

Cochliopina australis Morrison, 1946

Cochliopina australis Morrison, 1946; Smiths. Misc. Coll., 106: 23-24; pl. 2, fig. 13; pl. 3, fig. 14 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 37-38.

TYPE LOCALITY — Musselshell Creek just above the lagoon on the southeast end of Isla San José, Archipelago de Las Perlas, Panama. Holotype USNM 542165.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Cochliopina compacta (Pilsbry, 1910)

Cochliopa compacta Pilsbry, 1910; Nautilus, 23: 99; pl. 9, figs. 4-5 — Pilsbry, 1920; Proc. Acad. nat. Sci. Phila., 72: 197.

Cochliopina compacta (Pilsbry). Morrison, 1946; Smiths. Misc. Coll., 106: 19 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 38; fig. 33f.

TYPE LOCALITY — Río Choy, at the cave, south of Las Palmas, San Luís Potosí, México. Holotype ANSP 99007a.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Cochliopina dulcensis (Marshall, 1920)

Cochliopa dulcensis Marshall, 1920; Proc. U. S. Nat. Mus., 58: 302; pl. 17, figs. 1-3.

Cochliopina dulcensis (Marshall). Morrison, 1946; Smiths. Misc. Coll., 106: 19 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 38.

TYPE LOCALITY — Río Dulce, Dept. Izabal, Guatemala. Holotype USNM 336413.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Cochliopina extremis Morrison, 1946

Cochliopina extremis Morrison, 1946; Smiths. Misc. Coll., 106: 22-23; pl. 2, fig. 11; pl. 3, fig. 13 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 38.

TYPE LOCALITY — Small stream with a 100-yard lagoon just east of the southern tip of Isla San José, Archipelago de Las Perlas, Panama. Holotype USNM 542163.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Cochliopina francesae (Goodrich & Van der Schalie, 1937)

Cochiopa francesae Goodrich & Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 38; pl. 1, fig. 3.

Cochliopina francesae (Goodrich & Van der Schalie). Morrison, 1946; Smiths. Misc. Coll., 106: 19 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 38.

TYPE LOCALITY — Río de La Pasion, at the mouth of the Arroyo Chajchinic, northwest of Porvenir, Dept. Alta Verapaz, Guatemala. Holotype in the UMMZ.

DISTRIBUTION — Known from The Río de La Pasión, GUATEMALA, and the Río San Pedro, TABASCO, México.

Cochliopina fratercula Morrison, 1946

Cochliopina fratercula Morrison, 1946; Smiths. Misc. Coll., 106: 21-22; pl. 2, fig. 9; pl. 3, fig. 11 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 38.

TYPE LOCALITY — Río Mata Puerco, Isla San José, Archipelago de Las Perlas, Panama. Holotype USNM 542157.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Cochliopina guatemalensis (Morelet, 1851)

Valvata guatemalensis Morelet, 1951; Test. Noviss., II: 22 — Fischer & Crosse, 1892: 302; pl. 48, fig. 2-2b; pl. 50, fig. 1-1b.

Cochliopa guatemalensis (Morelet). Von Martens, 1899; Biol. Cent. Amer.: 428 — Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 198.

Cochliopina guatemalensis (Morelet). Morrison, 1946; Smiths. Misc. Coll., 106: 19 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 38-39.

TYPE LOCALITY — Río Michatoya, near the port of Istapa [Puerto Ixstapa], Dept. Esquintla, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known for certain only from the type locality.

Cochiopina hinkleyi (Pilsbry, 1920)

Cochliopa hinkleyi Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 198-199; fig. 4.

Cochliopina hinkleyi (Pilsbry). Morrison, 1946; Smiths. Misc. Coll., 106: 19 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 39.

TYPE LOCALITY — Lago de Izabal near Jocolo, Dept. Izabal, Guatemala. Holotype ANSP 46246a.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Cochliopina infundibulum (Von Martens, 1899)

Cochliopa infundibulum Von Martens, 1899; Biol. Cent. Amer.: 429; pl. 23, fig. 2 — Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 198.

Cochliopina infundibulum (Von Martens). Morrison, 1946; Smiths. Misc. Coll., 106: 19 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 39; fig. 22a.

TYPE LOCALITY — Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: Río Usumacinta System of TABASCO and CHIAPAS, México, and the Dept. Petén, Guatemala.

Cochliopina izabal (Pilsbry, 1920)

Cochliopa izabal Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 200-201; figs. 6a-f.

Cochliopa izabal perstriata Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 201; fig. 7.

Coichliopina izabal (Pilsbry). Morrison. 1946: 19 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 39.

TYPE LOCALITY — Lago de Izabal, near Jocolo, Dept. Izabal, Guatemala. Holotype ANSP 45638a.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Cochliopina juradoi Morrison, 1946

Cochliopina juradoi Morrison, 1946; Smiths. Misc. Coll., 106: 20-21; pl. 2, fig. 8; pl. 3, fig. 10 — Taylor, 1966; Veliger, 9: 176 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 39.

TYPE LOCALITY — Stream leading to the northwest mangrove marsh on Isla San José, Archipelago de las Perlas, Panama. Holotype USNM 542154.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Cochliopina milleri Taylor, 1966

Cochliopina milleri Taylor, 1966; Veliger, 9: 77; text-figs. 6-7; pl. 13, figs. 12-13 — Hershler, 1985; Malacologia, 26: 68-70; figs. 23a-h, 24-26 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 39.

TYPE LOCALITY — Río Mesquites at the main road 9 km southwest of Quatro Ciénegas, Coahuila. Holotype UMMZ 220182.

DISTRIBUTION RECORDS — COAHUILA: known only from the immediate vicinity of the type locality.

Cochliopina minor (Pilsbry, 1920)

Cochliopa minor Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 199-200; fig. 5.

Cochliopina minor (Pilsbry). Morrison, 1946; Smiths. Misc. Coll., 106: 19 — Taylor, 1966; Veliger, 9: 177 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 39.

TYPE LOCALITY — Polvon, Dept. León, Nicaragua. Holotype ANSP 58286.

DISTRIBUTION RECORDS — NICARAGUA: known only from the type locality.

Cochliopina navalis Morrison, 1946

Cochliopina navalis Morrison, 1946; Smiths. Misc. Coll., 106: 22; pl. 2, fig. 12; pl. 3, fig 12 — Taylor, 1966; Veliger, 9: 177 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 39.

TYPE LOCALITY — A small stream flowing into the southwestern bay, Isla San José, Archipelago de Les Perlas, Panama. Holotype USNM 542160.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Cochliopina picta (Pilsbry, 1910)

Cochliopa picta Pilsbry, 1910; Nautilus, 23: 100; pl. 9, figs. 1-2 — Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 197.

Cochliopina picta (Pilsbry). Morrison, 1946; Smiths. Misc. Coll., 106: 19 — Taylor, 1966; Veliger, 9: 177 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 39.

TYPE LOCALITY — Río Coy, near the ford on the road to Tampamolon, San Luís Potosí, México. Holotype ANSP 99013a.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the vicinity of the type locality, and the Río Ganina near Rascón.

Cochliopina riograndensis (Pilsbry & Ferriss, 1906)

Cochliopa riograndensis Pilsbry & Ferriss, 1906: 171, pl. 9, figs. 10-13 — Pilsbry, 1920; Proc. Acad. Nat. Sci. Phila., 72: 197.

Cochliopina riograndensis (Pilsbry & Ferriss). Morrison, 1946; Smiths. Misc. Coll., 106: 18 — Taylor, 1966; Veliger, 9: 177 — Hershler, 1985; Malacologia, 28: 71-72; fig. 23I — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 93-94.

TYPE LOCALITY — Río San Filipe, near the Río Grande, Val Verde County, Texas. Holotype ANSP 91324a.

DISTRIBUTION RECORDS — Streams in Val Verde County, Texas. COAHUILA: Quatro Ciénegas Basin. SAN LUÍS POTOSÍ: Río Valles. TAMAULIPAS: Río Panuco and Río Sabinas systems.

Cochliopina tryoniana (Pilsbry, 1890)

Cochliopa tryoniana Pilsbry, 1890; Nautilus, 4: 52 — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 331; pl. 15, fig. 12 — Von Martens, 1899; Biol. Cent. Amer.: 428-429; pl. 23, figs. 9-9c — Pilsbry, 1920: 198.

Cochliopina tryoniana (Pilsbry). Morrison, 1946; Smiths. Misc. Coll., 106: 18 — Taylor, 1966; Veliger, 9: 177 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 40.

TYPE LOCALITY — Polvón [= Palvón], Dept. León, Nicaragua. ANSP 58285a.

DISTRIBUTION RECORDS — NICARAGUA: Pacific coastal streams south to the Río Terraba, COSTA RICA.

Cochliopina wetmorei Morrison, 1946

Cochliopina wetmorei Morrison, 1946; Smiths. Misc. Coll., 106: 24-25; pl. 2, fig. 16; pl. 3, fig. 15 — Taylor, 1966; Veliger, 9: 177 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 40.

TYPE LOCALITY — Río Marina, east side of Isla San José, Archipelago de Las Perlas, Panama. Holotype USNM 542167.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Cochliopina zeteki Morrison, 1946

Cochliopina zeteki Morrison, 1946; Smiths. Misc. Coll., 106: 19-20; pl. 2, fig. 7; pl. 3, figs. 5, 9 — Taylor, 1966; Veliger, 9: 177 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 40.

TYPE LOCALITY — Dead leaves along the east margin of the Río Juan Diáz, just below the Las Sabanas Road bridge, east of Panama City, Panama Province, Panama. Holotype USNM 542152.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Genus Emmericiella Pilsbry, 1909

Emmericiella Pilsbry, 1909; Nautilus, 23: 46 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 42.

TYPE SPECIES — By original designation: Ememericia (Emmericiella) novamundi Pilsbry, 1909.

DISTRIBUTION — NORTH AMERICA: subterranean headwaters of the Río Choy, San Luis Potosí, México.

TAXONOMY — The genus contains two species.

Emmericiella longa (Pilsbry, 1909)

Emmericia (Emmericiella) longa Pilsbry, 1909; Nautilus, 23: 46; pl. 5, figs. 11-12.

Emmericiella longa (Pilsbry). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 44.

TYPE LOCALITY — Río Choy, Luis Potosí, México. Holotype ANSP 99022.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Emmericiella novimundi (Pilsbry, 1909)

Emmericia (Emmericiella) novimundi Pilsbry, 1909; Nautilus, 23: 46; pl. 5, figs. 9-10.

Emmericiella novimundi (Pilsbry). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 44-45; figs. 26-27.

TYPE LOCALITY — Banks of the Río Choy near the cave, San Luis Potosí, México. Holotype ANSP 99021a.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Genus Juturnia Hershler, Liu and Stockwell, 2002

Juturnia Hershler, Liu and Stockwell, 2002; Proc. Biol. Soc. Wash., 115: 172-175.

TYPE SPECIES — Durangonella coahiilae Taylor, 1966.

DISTRIBUTION — Lower Rio Grande region of North America.

TAXONOMY — Three species, one of which occurs in México.

Juturnia coahuilae ( Taylor, 1966)

Durangonella coahuilae Taylor, 1966; Veliger, 9: 184-186; pl. 14, figs. 19, 22 — Hershler, 1985; Malacologia, 26: 81-87; figs. 32-36 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 41; figs. 24b-d, 25.

Juturnia coahuilae (Taylor) — Hershler, Liu and Stockwell, 2002; Proc. Biol. Soc. Wash., 115: 175.

TYPE LOCALITY — Laguna Grande within about 300 m of the mouth of the Río Churince, and about 17 km southwest of Cuatro Ciénegas, Coahuila. Holotype UMMZ 220159.

DISTRIBUTION RECORDS — COAHUILA: endemic to the Cuatro Ciénegas Basin.

Genus Lithococcus Pilsbry, 1911

Lithococcus Pilsbry, 1911; Princeton Exp. Patagonia, 3: 602 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 61.

TYPE SPECIES — By original designation: Lithoglyphus multicarinatus Miller, 1878.

DISTRIBUTION — Pacific coastal streams from the Río Barú, Costa Rica south to the Rio Santiago system in northwest Ecuador.

TAXONOMY — Three species are recognized, one of which occurs in Costa Rica.

Lithococcus aletes Thompson and Hershler, 1991

Lithococcus aletes Thompson and Hershler, 1991: 676-677; fig. 6 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 63.

TYPE LOCALITY — Río Barú, 0.5 km above mouth of river, Puntarenas Prov., Costa Rica. Holotype FLMNH 36378.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Genus Littoridina Souleyet, 1852

Littoridina Souleyet, 1852: 563 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 63.

TYPE SPECIES — By original designation Littoridina guadichaudii Souleyet, 1952.

DISTRIBUTION — North America, Central America and South America: coastal streams and estuaries from Texas and Colima, México south to Ecuador.

HABITAT — Brackish marshes and freshwater streams.

TAXONOMY — Four species. Many tropical American hydrobioids have been described as species of Littoridina. Most of these now are placed in Heleobia (Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 63-66).

Littoridina crosseana (Pilsbry, 1910)

Amnicola crosseana Pilsbry, 1910; Nautilus, 23: 98; pl. 9, fig. 6.

Littoridina crosseana (Pilsbry). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 66-67; fig. 38a-d, 39a-b, 40c.

TYPE LOCALITY — Ponds at La Barra, Tampico, Tamaulipas, México. Holotype ANSP 99502a.

DISTRIBUTION RECORDS — Common in brackish marshes in the immediate area of Corpus Cristi, Texas. TAMAULIPAS: Tampico. TABASCO.

Littoridina microcona Thompson & Hershler, 1991

Littoridina microcona Thompson & Hershler, 1991; Proc. Biol. Soc. Wash., 104: 277-278; figs. 7 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 67-68; fig. 40a.

TYPE LOCALITY — Marshy pool 1.0 km north of Boca de Barranca, Puntarenas Prov., Costa Rica. Holotype FLMNH 175912.

DISTRIBUTION RECORDS — COSTA RICA: confined to brackish streams and marshes in Puntarenas Prov.

Littoridina orcutti (Pilsbry, 1928)

Amnicola orcutti Pilsbry, 1928; Proc. Acad. Nat. Sci. Phila., 80: 115-116; fig. 2.

Littoridina orcutti (Plsbry). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 67-68; fig. 40b.

TYPE LOCALITY — Manzanillo, Colima, México. Holotype ANSP 144801.

DISTRIBUTION RECORDS — Brackish marshes 2 km northeast of San Blas, NAYARIT southeast to the Laguna de Mitla, GUERRERO.

Genus Littoridinops Pilsbry, 1952

Littoridinops Pilsbry, 1952; Nautilus, 66: 51 — Thompson, 1968: 56 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 68.

TYPE SPECIES — By original designation Amnicola tenuipes Couper, 1844.

DISTRIBUTION — NORTH AMERICA. Atlantic coast of the United States from New Jersey south the Campeche, México; WEST INDIES, Bahama Islands, Grand Cayman Island, Cuba.

HABITAT — Brackish and freshwater.

TAXONOMY — Four species, one of which occurs in México.

Littoridinops tampicoensis (Pilsbry & Hinkley, 1907)

Paludestrina tampicoensis Pilsbry & Hinkley, 1907; Nautilus, 21: 39; pl. 5, fig. 13.

Littoridinops tampicoensis (Pilsbry & Hinkley). Taylor. 1966; Veliger, 9: 187 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 70-71.

TYPE LOCALITY — In river drift, Tampico, México. ANSP 93813a.

DISTRIBUTION RECORDS — TAMAULIPAS-VERACRUZ: known only the immediate vicinity of the type locality.

Genus Mesobia Thompson and Hershler, 1991

Mesobia Thompson & Hershler, 1991; Proc. Biol. Soc. Wash., 104: 679 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 74.

TYPE SPECIES — Mesobia pristina Thompson and Hershler, 1991.

DISTRIBUTION — Known only from Lago de Yajoa, Honduras.

HABITAT — Freshwater.

TAXONOMY — One species.

Mesobia pristina Thompson & Hershler, 1991

Mesobia pristina Thompson & Hershler, 1991; Proc. Biol. Soc. Wash., 104: 679-680; figs. 8 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 74; figs. 45a-d, 46a-c.

TYPE LOCALITY — Lago de Yajoa, at the north side of an island near Agua Azul, Dept. Cortéz, Honduras. Holotype FLMNH 40421.

DISTRIBUTION RECORDS — HONDURAS: known only from the type locality.

Genus Mexipyrgus Taylor, 1966

Mexipyrgus Taylor, 1966; Veliger, 9: 188 — Hershler, 1985; Malacologia, 26: 87 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 74.

TYPE SPECIES — Mexipyrgus carranzae Taylor, 1966.

DISTRIBUTION — NORTH AMERICA: endemic to the Cuatro Ciénegas Basin, Coahuila, México.

HABITAT — Freshwater.

TAXONOMY — The genus is monotypic.

Mexipyrgus carranzae Taylor, 1966

Mexipyrgus carranzae Taylor, 1966; Veliger, 9: 191; pl. 15, figs. 27-32; text-fig. 16 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 75-78; figs. 47a-d, 48a-c.

Mexipyrgus churinceanus Taylor, 1966; Veliger, 9: 190-191; pl. 16, figs. 33-39; pl. 17, figs. 40-41 — Hershler, 1985; Malacologia, 26: 87-105; figs. 37-45.

Mexipyrgus escobedae Taylor, 1966; Veliger, 9: 191-192; pl. 14, figs. 23-26.

Mexipyrgus lugoi Taylor, 1966; Veliger, 9: 192-193; pl. 17, figs. 42-45.

Mexipyrgus mojarralis Taylor, 1966; Veliger, 9: 193; pl. 18, figs. 46-49; 51-53.

Mexipyrgus multilineatus Taylor, 1966; Veliger, 9: 193-194; pl. 18, figs. 50, 54-57.

HOLOTYPES — Mexipyrgus carranzae: UMMZ 220211. Mexipyrgus churinceanus: UMMZ 220150. Mexipyrgus escobedae: UMMZ 220202. Mexipyrgus lugoi: UMMZ 220185. Mexipyrgus mojarralis: UMMZ 220192. Mexipyrgus multilineatus: UMMZ 220197.

TYPE LOCALITIES — Mexipyrgus carranzae Laguna Tio Candido, 14 km south of Cuatro Ciénegas. Mexipyrgus churinceanus: Laguna Churince, 16 km southwest of Cuatro Ciénegas. Mexipyrgus escobedae: Laguna Escobeda, 12 km south of Cuatro Ciénegas. Mexipyrgus lugoi: Río Mesquites at the main road 9 km southwest of Cuatro Ciénegas. Mexipyrgus mojarralis: West Laguna in El Mojarral, 1.7 km ENE of the northern tip of Sierra San Marcos. Mexipyrgus multilineatus: East Laguna in El Mojarral, 1.9 km ENE of the northern tip of Sierra San Marcos. All localities are in the Cuatro Ciénegas Basin, Coahuila.

DISTRIBUTION RECORDS — COAHUILA: endemic to the Cuatro Ciénegas Basin.

Genus Mexithauma Taylor, 1966

Mexithauma Taylor, 1966; Veliger, 9: 205 — Hershler, 1985; Malacologia, 26: 72 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 78.

TYPE SPECIES — Mexithauma quadripaludium Taylor, 1966.

DISTRIBUTION — México, endemic to the Cuatro Ciénegas basin, Coahuila.

HABITAT — Freshwater.

TAXONOMY — Monotypic.

Mexithauma quadripaludium Taylor, 1966

Mexithauma quadripaludium Taylor, 1966; Veliger, 9: 205-207; pl. 19, figs. 58-63; text-fig. 22 — Hershler, 1985; Malacologia, 26: 72-78; figs. 27-31 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 78-80; 79-80.

TYPE LOCALITY — Laguna Tio Candido, 9.3 km south of the northern tip of the Sierra de San Marcos, Cuatro Ciénegas Basin, Coahuila (Hershler, 1985). Holotype UMMZ 220214.

DISTRIBUTION RECORDS — COAHUILA: endemic to the Cuatro Ciénegas Basin (Hershler, 1985).

Genus Onobops Thompson, 1968

Onobops Thompson, 1968; Fla. Hydrob.: 28 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 83.

TYPE SPECIES — Onobops crassa Thompson, 1968.

DISTRIBUTION — Atlantic coast of the United States from Maryland south to Campeche, México.

HABITAT — Brackish marshes.

TAXONOMY — Two species occur in the southeastern United States. Numerous unidentified species samples are present in the Florida Museum of Natural History from the Gulf coastal region of the United States and México.

Genus Paludiscala Taylor, 1966

Paludiscala Taylor, 1966; Veliger, 9: 207 — Hershler, 1985; Malacologia, 26: 58 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 85.

TYPE SPECIES — Paludiscala caramba Taylor, 1966.

DISTRIBUTION — NORTH AMERICA: endemic to the Cuatro Ciénegas Basin, Coahuila, México.

HABITAT — Freshwater.

TAXONOMY — The genus is monotypic.

Paludiscala caramba Taylor, 1966

Paludiscala caramba Taylor, 1966; Veliger, 9: 207-208; pl. 13, figs. 11, 14, 16; text-figs. 23-25 — Hershler, 1985; Malacologia, 26: 59-64; figs. 19-22 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 85-87; figs. 55-56.

TYPE LOCALITY — Stream draining marsh due east of Majorral West Laguna, about 10 km south of Cuatro Ciénegas, Coahuila. Holotype UMMZ 220164.

DISTRIBUTION RECORDS — COAHUILA: springs in the Cuatro Ciénegas Basin (Hershler, 1985).

Genus Phreatoceras Hershler & Longley, 1987

Hadoceras Hershler & Longley, 1986; Proc. Biol. Soc. Wash., 99: 122-125. (Not Hadoceras Strand, 1934, Cephalopoda.)

Phreatoceras Hershler & Longley, 1987; Proc. Biol. Soc. Wash., 100: 402Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 87.

TYPE SPECIES — Hadoceras taylori Hershler & Longley, 1986.

DISTRIBUTION — NORTH AMERICA; Springs in Real County, Texas, and in the Cuatro Ciénegas Basin, Coahuila.

TAXONOMY — Monotypic.

Phreatoceras taylori (Hershler & Longley, 1986)

Hadoceras taylori Hershler & Longley, 1986b: 125-135; figs. 1-11.

Phreatoceras taylori (Hershler & Longley). Hershler & Longley, 1987: 402 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 87-89; figs. 57-58.

TYPE LOCALITY — Roaring Springs, Real County, Texas. Holotype USNM 849000.

DISTRIBUTION RECORDS — Known from springs in Real Co., and Williamson Co., Texas, and the Cuatro Ciénegas Basin, COAHUILA.

Genus Pyrgophorus Ancey, 1888

Pyrgophorus Ancey, 1888; Bull. Soc. Malac. France, 5: 188 — Taylor, 1966; Veliger, 9: 194 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 89.

TYPE SPECIES — Pyrgulopsis spinosus Pilsbry & Call, 1886.

DISTRIBUTION — West Indies, North America, Central America and South America; south Florida, the West Indies excluding the Bahama Islands and the Cayman Islands; coastal Mississippi, Louisiana, Texas, south though the coastal lowlands of east México to the Isthmus of Tehuantepec; lowland areas from Chiapas and Tabasco south through Central America to Ecuador on the Pacific coast, and the Caribbean-Atlantic drainage systems east and south to Pará State, Brazil.

HABITAT — Primarily freshwater; occasionally in brackish water.

TAXONOMY — The species-level systematics of Pyrgophorus is in need of study. Forty-five species and subspecies have been described on the basis of shell characters. The shells frequently bear ornate sculpture which varies greatly within and between populations. Similar ornate or smooth shell forms appear throughout the range of the genus. The assignment of names to specimens is highly subjective because most species and subspecies were not adequately diagnosed, illustrated or critically compared to related forms. Taylor (1966) and Hershler & Thompson (1992) review the taxonomic history of the nominate forms. It is uncertain if more than just a few of these are valid. The oldest species name for the genus is parvulus Guilding, 1828, described from the Windward Islands, West Indies. Most Méxican and Central America populations are referred by authors to Pyrgophorus coronatus (Pfeiffer, 1840). Names applicable to most other Méxican and Central American forms are listed in the synonymy given for coronatus. I am comfortable in recognizing only two species in México and Central America, Pyrgophorus coronatus (Pfeiffer, 1840) and Pyrgophorus exiguus (Morelet, 1851), although other nominate species are also retained in this list. Extralimital taxa are listed in Hershler & Thompson (1992: 91-94).

Pyrgophorus coronatus (Pfeiffer, 1840)

Paludina coronata Pfeiffer, 1840: 253 — Kúster, 1852; in Martini & Chemnitz, Syst. Conch. Cab., ed. 2 (Paludina): 51; pl. 11, figs. 11-12.

Hydrobia coronata (Pfeiffer). Von Martens, 1858; in Wiegmann’s Archis f. Naturg., 24: 192.

Amnicola coronata (Pfeiffer). Fischer, 1860; Jour. de Conchyl., 8: 363.

Pyrgulopsis coronatus (Pfeiffer). Ancey, 1888; Bull. Soc. Malac. France, 5: 197.

Potamopyrgus coronatus (Pfeiffer). Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 34: 328.

Pyrgophorus coronatus. Taylor, 1966; Veliger, 9: 194.

Paludina crystallina Pfeiffer, 1840: 253. (Matanzas, Matanzas Province, Cuba [Aguayo and Jaume, 1947].)

Melania spinifera C. B. Adams, 1845: 17. (Jamaica.)

Paludina jamaicensis C. B. Adams, 1849. (Jamaica.)

Paludina cisternicola Morelet, 1851; Test. Noviss., II: 21. (Campeche, Campeche, México.)

Paludina ornata Morelet, 1851; Test. Noviss., II: 21. (Lago de Coatepeque, El Salvador.)

Paludina cisternina Küster, 1852: 51; pl. 10, figs. 9-10. (Bay of Campeche, México.)

Amnicola candeana inermis Fischer, 1860; Jour. de Concyl., 8: 363. (Type locality not stated.)

Amnicola candeana gibbosa Fischer, 1860; Jour. de Conchyl., 8: 364. (Bay of Campeche, México.)

Hydrobia reevei Frauenfeld, 1863: 526; pl. 8.

Pyrgulopsis nicaraguanus Ancey, 1888; Bull. Soc. Malac. France, 5: 194. (Nicaragua.)

Pyrgula nicaraguensis Newcomb, MS; in Ancey, 1888; Bull. Soc. Malac. France, 5: 194.

Pyrgulopsis nicaraguanus costuliferus Ancey, 1888; Bull. Soc. Malac. France, 5: 195. (Nicaragua.)

Purgulopsis nicaraguanus duplicatus Ancey, 1888; Bull. Soc. Malac. France, 5: 195. (Nicaragua.)

Pyrgulopsis newcombianus Ancey, 1888; Bull. Soc. Malac. France, 5: 196. (Nicaragua.)

Pyrgulopsis productus Ancey, 1888; Bull. Soc. Malac. France, 5: 197. (Nicaragua.)

Purgulopsis wrighti Ancey, 1888; Bull. Soc. Malac. France, 5: 199. (Lago de Coatepeque, El Salvador.)

Pyrgulopsis wrighti plicosus Ancey, 1888; Bull. Soc. Malac. France, 5: 199. (Lago de Coatepeque, El Salvador).

Pyrgulopsis wrighti transitans Ancey, 1888; Bull. Soc. Malac. France, 5: 200. (Lago de Coatepeque, El Salvador).

Pyrgulopsis wrighti oblongus Ancey, 1888; Bull. Soc. Malac. France, 5: 200. (Lago de Coatepeque, El Salvador).

Pyrgulopsis wrighti minimus Ancey, 1888; Bull. Soc. Malac. France, 5: 201. (Lago de Coatepeque, El Salvador).

Pyrgulopsis wrighti obesus Ancey, 1888; Bull. Soc. Malac. France, 5: 201. (Lago de Coatepeque, El Salvador).

Amnicola coronata unicarinata Von Martens, 1899; Biol. Cent. Amer.: 433-434. Type locality not stated. Here restricted to Veracruz, Veracruz, México. Earlier, Von Martens (1873) recorded this form from Vieque. Taylor (1966) and Hershler & Thompson (1992) listed unicarinatus as a nomum nudum, but the form is diagnosed by Von Martens (1899: 431), and he cites the description and figure given by Strebel (1873: 34: pl. 5, fig. 34a), thus validating the use of the name.

Pyrgulopsis coronatus Ancey, 1888; Bull. Soc. Malac. France, 5: 198 (non Paludina coronata Pfeiffer, 1840). (Veracruz, México).

TYPE LOCALITY — Matanzas, Matanzas Province, Cuba (Aguayo and Jaume, 1947).

DISTRIBUTION RECORDS — Coastal and lowland regions of México from Tamaulipas and Oaxaca south to Venezuela; West Indies in general.

Pyrgophorus chagresensis (Morrison, 1946)

Lyrodes chagresensis Morrison, 1946; Smiths. Misc. Coll., 106: 16-16; pl. 2, fig. 6; pl. 3, fig. 6.

Pyrgophorus chagresensis (Morrison). Taylor, 1966; Veliger, 9: 194 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 92.

TYPE LOCALITY — Río Chagres near Gatuncillo, Dept. Panama, Panama. Holotype USNM 542149.

DISTRIBUTION RECORDS — PANAMA: recorded only from the type locality.

Pyrgophorus conoideus (Ancey, 1888)

Pyrgulopsis conoideus Ancey, 1888; Bull. Soc. Malac. France, 5: 196.

Pyrgophorus conoideus (Ancey) — Taylor, 1966; Veliger, 9: 194 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 92.

TYPE LOCALITY — Nicaragua.

DISTRIBUTION RECORDS — NICARAGUA: uncertain distribution.

Pyrgophorus hydrobioides (Ancey, 1888)

Pyrgulopsis hydrobioides Ancey, 1888; Bull. Soc. Malac. France, 5: 201.

Amnicola (?) hydrobioides (Ancey). Von Martens, 1899; Biol. Cent. Amer.: 435-436.

Pyrgophorus hydrobioides (Ancey). Taylor, 1966; Veliger, 9: 194 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 93.

TYPE LOCALITY — Lago Coatepeque, El Salvador.

DISTRIBUTION RECORDS — EL SALVADOR: known only from the type locality.

REMARKS — Von Martens (1899) suggests that the type is a mislabeled specimen of Hydrobia ulvae from the coast of France.

Pyrgophorus spinosus (Call & Pilsbry, 1886)

Pyrgulopsis spinosus Call & Pilsbry, 1886; Proc. Davenport Acad. Nat. Sci., 5: 14, pl. 2, figs. 17-19.

Potamopyrgus spinosus (Call & Pilsbry) — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 327 — Walker, 1918; Misc. Pub. Mus. Zool. Univ. Mich., (6): 140.

Hydrobia texana Pilsbry, 1887; Proc. Davenport Acad. Nat. Sci., 5: 33; pl. 3, figs. 1-6. (Guadelupe River and Comal Creek, New Braunfels, Comal County, Texas.)

Pyrgulopsis spinosus brevispira Ancey, 1888; Bull. Soc. Malac. France, 5: 193. (Comal Creek, New Braunfels, Comal, County, Texas.)

Pyrgophorus spinosus (Call & Pilsbry). Taylor, 1966; Veliger, 9: 195 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 93.

TYPE LOCALITY — Comal Creek, New Braunfels, Comal County, Texas. Syntypes of Potamopyrgus spinosus: not located. Lectotype of Hydrobia texanus: ANSP 68908a (H. B. Baker, 1964)

DISTRIBUTION RECORDS — South Central Texas, including the Rio Bravo del Norte (Rio Grand), COAHUILA and CHIHUAHUA.

REMARKS — Pilsbry (1891) found little reason for retaining spinosus as a distinct species from coronatus.

Pyrgophorus zeteki (Morrison, 1946)

Lyrodes zeteki Morrison, 1946; Smiths. Misc. Coll., 106: 17; pl. 2, fig. 10.

Pyrgophorus zeteki (Morrison). Taylor, 1966; Veliger, 9: 195 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 94.

TYPE LOCALITY — Pedro Miguel, Canal Zone, Panama. Holotype USNM 432871.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Genus Subcochliopa Morrison, 1946

Subcochliopa Morrison, 1946; Smiths. Misc. Coll., 106: 25 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 99.

TYPE SPECIES — Subcochliopa trochus Morrison, 1946.

DISTRIBUTION — Pacific coastal streams of Panama and Costa Rica.

HABITAT — Brackish water and freshwater zone immediately above brackish zone.

TAXONOMY — Three species are recognized.

Subcochliopa colabrensis Morrison, 1946

Subcochliopa colabrensis Morrison, 1946; Smiths. Misc. Coll., 106: 26; pl. 2, fig. 14; pl. 3, fig. 16 — Taylor, 1966; Veliger, 9: 179 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 101.

TYPE LOCALITY — Río Colabre [Río Culebra], Río Bayamo drainage, Panama Province, Panama. Holotype USNM 542169.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Subcochliopa trochulus (Von Martens, 1899)

Cochliopa trochulus Von Martens, 1899; Biol. Cent. Amer.: 429; pl. 23, fig. 2

Subcochliopa trochulus (Von Martens). Morrison, 1946; Smiths. Misc. Coll., 106: 25 — Taylor, 1966; Veliger, 9: 197 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 101.

TYPE LOCALITY — Here restricted to El Pozo, Río Grande de Terraba, Puntarenas Province, Costa Rica.

DISTRIBUTION RECORDS — Southwestern COSTA RICA. In addition to the type locality the species has been recorded from marshes at Sierpe.

Subcochliopa trochus Morrison, 1946

Subcochliopa trochus Morrison, 1946; Smiths. Misc. Coll., 106: 25-26 — Taylor, 1966; Veliger, 9: 179 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 99-101; figs. 65a, d (shell), 65b (operculum), 65e (radula), 66 (reproductive system).

TYPE LOCALITY — Sona, Río Tribique, Veraguas Prov., Panama. Holotype USNM 542168.

DISTRIBUTION RECORDS — PANAMA. occurring in smaller streams draining into the Río San Pablo, Veraguas Prov: Quebrada Tolerique, 3 km SE of Sona; Rio San Juan, 2.5 km SE of Soledad.

Genus Tepalcatia Thompson & Hershler, 2002

Tepalcatia Thompson & Hershler, 2002; Proc. Biol. Soc. Wash., 115: 196.

TYPE SPECIES — By original designation Tepalcatia tela Thompson & Hershler, 2002.

DISTRIBUTION — The Rio Balsas basin of southern México.

HABITAT — Freshwater springs and streams.

TAXONOMY — Three species are recognized.

Tepalcatia bakeri (Pilsbry, 1891)

Potamopyrgus ? bakeri Pilsbry, 1891; Nautilus, 5: — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 328-329; pl. 15, figs. 9-11 — Fischer & Crosse, 1891; Miss. Sci. Mex., II: 277 — Baker, 1964; Proc. Acad. Nat. Sci. Phila., 116: 171 (lectotype selection).

Amnicola bakeri (Pilsbry, 1891). Von Martens, 1899; Biol. Cent. Amer.: 435.

Tryonia bakeria (Pilsbry, 1891). Taylor, 1966; Veliger, 9: 196.

Tepalcatia bakeri (Pilsbry, 1891). Thompson & Hershler, 2002; Proc. Biol. Soc. Wash., 115: 203; fig. 12.

TYPE LOCALITY — Specimens were dug from the bank of a stream east of Yauntepec, Morelos. Lectotype ANSP 61578 (Thompson & Hershler).

DISTRIBUTION RECORDS — MORELOS: known only from the type locality.

Tepalcatia polia (Thompson & Hershler, 1991)

Aroapyrgus polius Thompson & Hershler, 1991; Proc. Biol. Soc. Wash., 104: 669-671; fig. 1 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 28.

Tepalcatia polia (Thompson & Hershler). Thompson & Hershler, 2002; Proc. Biol. Soc. Wash., 115: 197-202; figs. 8-11.

TYPE LOCALITY — A small spring-fed pool 3.5 km northeast of Tamazulapán del Progreso, Oaxaca, México. Holotype FLMNH 175028.

DISTRIBUTION RECORDS — OAXACA: known only from the type locality.

Tepalcatia tela Thompson & Hershler, 2002

Tepalcatia tela Thompson & Hershler, 2002; Proc. Biol. Soc. Wash., 115: 192-197; figs. 2-7.

TYPE LOCALITY — A stream (Los Ultimos) 3.0 km north of Santa Ana Amitlán, Michoacán, 430 m alt.; 19º10.7’N, 102º32.1’ W. Holotype FLMNH 287449.

DISTRIBUTION RECORDS — MICHOACÁN: in addition to the type locality this snail is known from a spring-fed lagoon, La Mojada, 7.5 km NW of Apatzingan.

Genus Texadina Abbott & Ladd, 1951

Texadina Abbott & Ladd, 1951; Jour. Wash. Acad. Sci., 41: 335 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 102.

TYPE SPECIES — Littoridina (Texadina) sphinctostoma Abbott & Ladd, 1951.

DISTRIBUTION — Gulf of México coast of the United States from Pensacola Bay, Florida west and south to the Laguna de Terminos, Campeche, México; Jamaica.

HABITAT — Brackish marshes.

TAXONOMY — Two species are recognized. One occurs in Mexico.

Texadina sphinctostoma (Abbott & Ladd, 1951)

Littoridina (Texadina) sphinctostoma Abbott & Ladd, 1951; Jour. Wash. Acad. Sci., 41: 335, text-figs. 1-12 — Solem, 1961; Nautilus, 74: 158.

Texadina sphinctostoma (Abbott & Ladd). Taylor, 1966; Veliger, 9: 196 — Garcia-Cubas, 1963; Bol. Inst. Geol. Univ. Nac. Aut. Méx., 67: 1-55 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 102-105; figs. 67a, c (shell), 67b (operculum), 67a (radula), 68 (reproductive anatomy).

TYPE LOCALITY — 1.5 miles north of Webb Point, northwest side of San Antonia Bay, 27 miles northeast of Rockport, Texas. Holotype USNM 596722.

DISTRIBUTION RECORDS — Marshes along the Gulf of México coast from Pensacola Bay, Florida, west and south to Campeche. The only record in México is the Laguna de Terminos, CAMPECHE (Garcia-Cubas, 1963).

Genus Tryonia Stimpson, 1865

Tryonia Stimpson, 1865; Smiths. Misc. Coll., (201): 54 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 107. (Type species: Tryonia clathrata Stimpson, 1865.) — Hershler, 2001; Smiths. Contrib. Zool., (612): 3-5.

Calipyrgula Pilsbry, 1934; Nautilus, 48: 15. (Type species: Calipyrgula carinifera Pilsbry, 1934.)

Durangonella Morrison, 1945: 20 — Taylor, 1966; Veliger, 9: 184 — Hershler, 1985; Malacologia, 26: 78-80 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 40-41. (Type species: Hydrobia seemani Frauenfeld, 1863.)

Hyalopyrgus Thompson, 1968: 43. (Type species: Bythinella aequicostata Pilsbry, 1889.)

Paupertryonia Taylor, 1987; Bulletin of the New Mexico Bureau of Mines and Mineral Resources, 116: 41. (Type species: Potamopyrgus cheatumi Pilsbry, 1935.)

DISTRIBUTION — NORTH AMERICA: northern Sonora and Chihuahua, México; southwestern desert region of California, Nevada, Utah, Arizona, New México and western Texas, and in the southeast in the central part of the Florida Peninsula.

HABITAT — Freshwater.

TAXONOMY — The genus includes about 16 Recent species (Hershler, 2001). Two occur in México. Hershler, Liu and Stockwell (2002) demonstrate that the type species of Durangonella is a Tryonia. Three other species that are known only from shells were described as species of Durangonella, and they are assigned to Tryonia tentatively.

Tryonia dugesiana (Morrison, 1945)

Durangonella dugesiana Morrison, 1945; Nautilus, 59: 21; pl. 3, fig. 3 — Taylor, 1966; Veliger, 9: 184 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 42.

TYPE LOCALITY — Andocutira, Michoacán (amended to Andocutin, Guanajuato by Taylor, 1966). Holotype USNM 433473.

DISTRIBUTION RECORDS — GUANAJUATO: known only from the type locality.

Tryonia exiguus (Morelet, 1851)

Melania exigua Morelet, 1851; Test. Noviss., II: 23.

Tryonia exigua (Morelet). Fischer & Crosse, 1891; Miss. Sci. Mex., II: 275; pl. 50, figs. 2-2b — Von Martens, 1899; Biol. Cent. Amer.: 436 — Taylor, 1966; Veliger, 9: 197 — Hershler, 2001; Smith. Contrib. Zool., (612): 9.

Paludestrina exigua (Morelet). Goodrich and Van der Schalie, 1937; Misc. Pub. Mus. Zool. Univ. Mich., (34): 36.

Pyrgophorus exigua (Morelet). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 93, 94.

Melania minuta Brot, 1862: 42.

TYPE LOCALITY — Lago de Petén Itza, Dept. Petén, Guatemala.

DISTRIBUTION RECORDS — GUATEMALA: known only from the type locality.

Tryonia hertleini (Drake, 1956)

Lyrodes hertleini Drake, 1956; Bull. South. Calif. Acad. Sci., 55: 44-46; pl. 15.

Tryonia hertleini (Drake). Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 110 — Hershler, 2001; Smith. Contrib. Zool., (612): 10.

TYPE LOCALITY — Springs, Las Palomas, Chihuahua. Holotype CAS 9982.

DISTRIBUTION RECORDS — Known only from the type locality. Possibly extinct.

Tryonia mariae (Morrison, 1945)

Durangonella mariae Morrison, 1945; Nautilus, 59: 20; pl. 3, fig. 2 — Taylor, 1966; Veliger, 9: 184 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 42.

TYPE LOCALITY — One meter below the bed of the presently dry Lago de Tlahuac, 20 km east of Xochimilco, Distrito Federal, México. Holotype USNM 433399.

DISTRIBUTION RECORDS — DISTRITO FEDERAL, MEXICO: known only from the type locality.

Tryonia pilsbryi (Morrison, 1945)

Durangonella pilsbryi Morrison, 1945; Nautilus, 59: 22; pl. 3, fig. 4 — Taylor, 1966; Veliger, 9: 184 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 42.

TYPE LOCALITY — Paso del Río, Colima. Holotype USNM 362551.

DISTRIBUTION RECORDS — COLIMA: known only from the type locality.

Tryonia seemani (Frauenfeld, 1863)

Hydrobia seemani Frauenfeld, 1863: 1025 — Frauenfeld, 1865: 1; pl. 8, fig. 1 — Fischer & Crosse, 1891; Miss. Sci. Mex., II: 271.

Amnicola (?) seemanni (Frauenfeld). Von Martens, 1899; Biol. Cent. Amer.: 435.

Durangonella seemani (Frauenfeld). Morrison, 1945: 20 — Taylor, 1966; Veliger, 9: 184 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 42.

Tryonia seemani (Frauenfeld). Hershler, Liu and Stockwell, 2002; Proc. Biol. Soc. Wash., 115:.

TYPE LOCALITY — Durango (it is not clear whether Frauenfeld intended this to mean the city or the state). Cotypes in the Vienna Naturhistorisches Museum.

DISTRIBUTION RECORDS — DURANGO: known only from a spring at Ciudad Durango, which was a domestic water source for the city many years earlier. Possibly extinct.

Genus Zetekina Morrison, 1947

Zetekella Morrison, 1946; Smiths. Misc. Coll., 106: 11. (Type species by original designation: Littoridina frenata Pilsbry, 1935; non Zetekella Drake, 1944, Hemiptera.)

Zetekina Morrison, 1947; Nautilus, 60: 102. Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 112-114.

DISTRIBUTION — Streams along the Pacific drainage of Nicaragua, Costa Rica and Panama.

HABITAT — Brackish water and freshwater just above the brackish zone.

TAXONOMY — Seven species are recognized.

Zetekina frenata (Pilsbry, 1935)

Littoridina frenata Pilsbry, 1935: 5; text-figs. 1-1a.

Zetekella frenata (Pilsbry). Morrison, 1946; Smiths. Misc. Coll., 106: 12.

Zetekina frenata (Pilsbry). Morrison, 1947; Nautilus, 60: 102 — Taylor, 1966; Veliger, 9: 198 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 114; figs. 73a, 73d (shell).

TYPE LOCALITY — Río Juan Diaz, Panama City, Panama Prov., Panama. Holotype ANSP 161776.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Zetekina kompi (Morrison, 1946)

Zetekella kompi Morrison, 1946; Smiths. Misc. Coll., 106: 13; pl. 2, fig. 2; pl. 3, fig. 2.

Zetekina kompi (Morrison). Taylor, 1966; Veliger, 9: 198 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 114.

TYPE LOCALITY — Río Mata Puerco, west side of Isla San José, Archipelago de Las Perlas, Panama. Holotype USNM 542140.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality.

Zetekina martensi (Pilsbry, 1935)

Littoridina martensi Pilsbry, 1935; Proc. Acad. Nat. Sci. Phila., 87: 5; text-fig. 2.

Zetekella martensi (Pilsbry). Morrison, 1946; Smiths. Misc. Coll., 106: 11.

Zetekina martensi (Pilsbry). Taylor, 1966; Veliger, 9: 198 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 114.

TYPE LOCALITY — Río Fula, Dept. León, Nicaragua. Holotype ANSP 27227.

DISTRIBUTION RECORDS — Known only from the type locality.

Zetekina melanioides (Von Martens, 1899)

Amnicola melanioides Von Martens, 1899; Biol. Cent. Amer.: 439; pl. 22, fig. 8.

Littoridina melanioides (Von Martens). Pilsbry, 1935; Proc. Acad. Nat. Sci. Phila., 87: 5.

Zetekella melanioides (Von Martens). Morrison, 1946; Smiths. Misc. Coll., 106: 11.

Zetekina melanioides (Von Martens). Taylor, 1966; Veliger, 9: 198 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 115.

TYPE LOCALITY — Golfo Dulce, Río de los Platanales, Puntarenas Prov., Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality.

Zetekina panamensis (Bartsch, 1920)

Syncera panamensis Bartsch, 1920; Bull. U. S. Nat. Mus., 58: 164; pl. 12, fig. 8.

Zetekella panamensis (Bartsch). Morrison, 1946; Smiths. Misc. Coll., 106: 11.

Zetekina panamensis (Bartsch). Taylor, 1966; Veliger, 9: 198.

TYPE LOCALITY — Río Matasnillo, Panama. Holotype USNM 150870.

DISTRIBUTION RECORDS — PANAMA: known only from the type locality. Apparently extinct.

Zetekina tenuis (Von Martens, 1899)

Amnicola melanioides tenuis Von Martens, 1899; Biol. Cent. Amer.: 436; pl. 22, fig. 9.

Littoridina tenuis (Von Martens). Pilsbry, 1935; Proc. Acad. Nat. Sci. Phila., 87: 5.

Zetekella tenuis (Von Martens). Morrison, 1946; Smiths. Misc. Coll., 106: 11.

Zetekina tenuis (Von Martens). Taylor, 1966; Veliger, 9: 198 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 112.

TYPE LOCALITY — In a small stream running into the Río Boto, Golfo Dulce, Puntarenas Prov., Costa Rica.

DISTRIBUTION RECORDS — COSTA RICA: known only from the type locality and from marshes at Seripe, Puntarenas Prov. (Von Martens, 1899).

Zetekina veraguasensis (Morrison, 1946)

Zetekella veraguasensis Morrison, 1946; Smiths. Misc. Coll., 106: 12, pl. 2, fig. 1; pl. 3, fig. 1.

Zetekina veraguasensis (Morrison). Taylor, 1966; Veliger, 9: 198 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 115.

TYPE LOCALITY — Río Tribique, Sona, Veraguas Prov., Panama. Holotype USNM 542139.

DISTRIBUTION RECORDS — PANAMA: streams draining into the Río San Pablo, Veraguas Prov.

Subfamily LITHOGLYPHINAE Tryon, 1866

Genus Pterides Pilsbry, 1909

Pterides Pilsbry, 1909; Nautilus, 23: 48 — Herhsler & Thompson, 1992; Malac. Rev., Supp. 5: 130.

TYPE SPECIES — Pterides pterostoma Pilsbry, 1909.

DISTRIBUTION — Río Choy and Río Ganina in eastern San Luís Potosí, México.

TAXONOMY — Three species are recognized.

Pterides bisinulabris Pilsbry, 1909

Pterides bisinulabris Pilsbry, 1909; Nautilus, 23: 48-49; pl. 5, figs. 7-8.

TYPE LOCALITY — Río Ganina, three miles southwest of San Dieguito, San Luís Potosí. Holotype ANSP 99015.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Pterides pterostoma Pilsbry, 1909

Pterides pterostoma Pilsbry, 1909; Nautilus, 23: 48; pl. 5, figs. 1-2, 5-6 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 130.

TYPE LOCALITY — Not given. Holotype ANSP 99016a.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ (?): unknown.

Pterides rhabdus Pilsbry, 1909

Pterides rhabdus Pilsbry, 1909; Nautilus, 23: 48; pl. 5, figs. 3-4.

TYPE LOCALITY — Río Choy near the cave, San Luís Potosí. Holotype ANSP 99107.

DISTRIBUTION RECORDS — SAN LUÍS POTOSÍ: known only from the type locality.

Subfamily NYMPHOPHILINAE Taylor, 1966

Genus Pyrgulopsis Call & Pilsbry, 1886

Pyrgulopsis Call & Pilsbry, 1886; Proc. Davenport Acad. Sci., 5: 9 — Hershler & Thompson, 1987; Nautilus, 101: 28-31 — Hershler, 1994; Smith. Contri. Zool., (554): 5-14 — Liu & Hershler, 2005; Molecular phylogeny and Evolution, 34: 284-298. (Type species by original designation: Pyrgula nevadensis Stearns, 1883.)

Fontelicella Gregg & Taylor, 1965: 103. (Type species by original designation: Fontelicella californiensis Gregg & Taylor, 1965.)

Natricola Gregg & Taylor, 1965: 108. (Type species by original designation: Pomatiopsis robusta Walker, 1908.)

Microamnicola Gregg & Taylor, 1965: 109. (Type species by original designation: Amnicola micrococcus Pilsbry, 1893.)

Nymphophilus Taylor, 1966. (Type species by original designation: Nymphophilus minkleyi Taylor, 1966.)

Savaginius Taylor, 1966a: 130. (Type species by original designation: Paludestrina nana Chamberlain & Berry, 1933.)

Mexistiobia Hershler, 1985; Malacologia, 26: 46. (Type species by original designation: Mexistiobia manantiali Hershler, 1985.)

Apachecoccus Taylor, 1987: 32. (Type species by original designation: Apachecoccus arizonae Taylor, 1987.)

Yaquicoccus Taylor, 1987: 34. (Type species by original designation: Yaquicoccus bernardinus Taylor, 1987.)

DISTRIBUTION — Western North America, including the Snake River basin, California coastal drainages, Baja California, Colorado River basin, Rio Grande basin, Pecos River basin and internal drainages of northern México.

TAXONOMY — About 125 species are currently recognized. Seven occur in México.

Pyrgulopsis acarinatus (Hershler, 1985)

Nymphophilus acarinatus Hershler, 1985; Malacologia, 26: 45; fig. 9 (shell).

Pyrgulopsis acarinata (Hershler). Liu & Hershler, 2005; Molecular Phylogeny and Evolution, 34: 296.

TYPE LOCALITY — A large spring along a dirt road, 10.7 km south of the tip of the Sierra de San Marcos, Cuatro Ciénegas Basin, Coahuila. Holotype ANSP 355255.

DISTRIBUTION RECORDS — COAHUILA: known only from the type locality and Santa Tecla Laguna, 22 km south of the tip of the Sierra de San Marcos.

Pyrgulopsis brandi (Drake, 1953)

Amnicola brandi Drake, 1953; Jour. Wash. Acad. Sci., 43: 27; figs. 1-6 — Taylor, 1975; Pap. Paleo. Mus. Paleo. Univ. Mich., 10: 44.

Pyrgulopsis brandi (Drake). Hershler, 1994; Smith. Contrib. Zool., (554): 22-23; figs. 4e (female anatomy), 9g (shell), 9h-i (operculum), 33b (radula), 44b (penis).

TYPE LOCALITY — Springs at Las Palomas, Chihuahua, México. Holotype USNM 601494.

DISTRIBUTION RECORDS — CHIHUAHUA: known only from the type locality. Presumed to be extinct due to drying up of springs at the type locality.

Pyrgulopsis cedrosensis (Pilsbry, 1927)

Paludestrina cedroensis Pilsbry, 1927: 188; fig. 3.

Fontelicella cedroensis (Pilsbry). Gregg & Taylor, 1965: 108 — Taylor, 1976: 55.

Pyrgulopsis cedroensis (Pilsbry). Hershler, 1994; Smith. Contri. Zool., (554): 27-28; figs. 11d (shell), 11e-f (operculum), 34a (radula).

TYPE LOCALITY — Bernstein’s Spring on east side of Cedros Island, Baja California Norte, México. Holotype ANSP 141408.

DISTRIBUTION RECORDS — BAJA CALIFORNIA NORTE: apparently endemic to springs on Cedros Island. Not found in recent years.

Pyrgulopis chihuahua (Pilsbry, 1928)

Fluminicola chihuahua Pilsbry, 1928: 116; fig. 3 — H. B. Baker, 1964: 171.

Cochliopa chihuahua (Pilsbry). Pilsbry, 1935: 92 — Taylor, 1966; Veliger, 9: 179 — Taylor, 1967: 153 — Taylor, 1975: 56.

Pyrgulopsis chihuahua (Pilsbry). Hershler, 1994; Smith. Contri. Zool., (554): 28-32; figs. 12a-b (shell), 12c-d (operculum), 34b (radula), 45a (penis).

TYPE LOCALITY — Ojo Caliente de Santa Rosa, north-central Chihuahua (Taylor, 1967). Holotype ANSP 141266 (Baker, 1964: 171).

DISTRIBUTION RECORDS — CHIHUAHUA: known from the type locality, and from Ojo Caliente de Rosetilla, east of Delicias.

Pyrgulopsis manantiali (Hershler, 1985)

Mexistiobia manantiali Hershler, 1985; Malacologia, 26: 47-53; figs. 10-11 (shell), 12 (radula), 13 (external morphology), 14 (female reproductive system).

Pyrgulopsis manantiali (Hershler). Hershler & Thompson, 1987: 29, fig. 8 (penis) — Hershler, 1994; Smith. Contri. Zool., (554): 47; figs. 19a (shell), 19b-c (operculum), 37a (radula),48a (penis).

TYPE LOCALITY — A small spring 100 m south of Rio Mesquites at Tierra Blanca, Cuatro Ciénegas basin, Coahuila. Holotype ANSP 355205.

DISTRIBUTION RECORDS — COAHUILA: known only from the Cuatro Ciénegas basin.

Pyrgulopsis minkleyi (Taylor, 1966)

Nymphophilus minkleyi Taylor, 1966; Veliger, 9: 199-203; pl. 13, figs. 15, 17; text-figs. 17-19 (shell), 20 (operculum), 21 (penis) — Thompson, 1979; Malac. Rev., 12: 41-46; figs. 1-7 (shell), 8-9 (nervous system), 10 (radula), 11-15 (reproductive anatomy) — Hershler, 1985; Malacologia, 26: 40-45; fig. 4 (shell), fig. 5a (head), fig. 5b (operculum), fig. 6 (radula), fig. 7 (female reproductive anatomy), fig. 8 (male reproductive anatomy).

Pyrgulopsis minkleyi (Taylor). Liu & Hershler, 2005; Molecular phylogeny and evolution, 34: 296.

TYPE LOCALITY — Río Mesquites at the main road 9 km southwest of Cuatro Ciénegas, Coahuila. Holotype UMMZ 220188.

DISTRIBUTION RECORDS — COAHUILA: endemic to the Cuatro Ciénegas basin.

Pyrgulopsis palomasensis (Pilsbry, 1895)

Bythinella palomasensis Pilsbry, 1895; Nautilus, 9: 68 — Dall, 1897; Proc. U. S. Nat. Mus., 19: 369; pl. 31, fig. 9 (shell) — Pilsbry, 1916; Nautilus, 29: 111 — Drake, 1953; Jour. Wash. Acad. Sci., 43: 27 — Drake, 1956; Bull. South. Calif. Acad. Sci., 55: 46 — Taylor, 1967; Veliger, 10: 156.

Amnicola palomasensis (Pilsbry). Von Martens, 1899; Biol. Cent. Amer.: 134.

Fontelicella palomasensis (Pilsbry). Taylor, 1975; Pap. Paleo. Mus. Paleo. Univ. Mich., 10: 141.

Pyrgulopsis palomasensis (Pilsbry). Hershler, 1994; Smith. Contri. Zool., (554): 57-58; figs. 22 (shell).

TYPE LOCALITY — Laguna de Palomas, 1.6 km south of International Boundary Survey Monument Number 21, Mimbres Valley, Chihuahua (Taylor, 1967). Lectotype USNM 130016 (Hershler, 1994).

DISTRIBUTION RECORDS — CHIHUAHUA: known only from the type locality.

Subfamily incerti sedis

Genus Rachipteron Thompson, 1964

Rachipteron Thompson, 1964; Rev. Biol. Trop., 12: 97-98 — Taylor, 1966; Veliger, 9: 171 — Hershler & Thompson, 1992; Malac. Rev., Suppl. 5: 4. (Type species by monotypy: Rachipteron philopelum Thompson, 1964.)

DISTRIBUTION — Brackish marshes along the Pacific coast of Costa Rica.

TAXONOMY — The family relationships of the genus remain in question. Taylor (1966) suggests a relationship with the Stenothyridae, an East Asian family of brackish water snails. Higher group relationships cannot be resolved until the female reproductive anatomy is examined. The genus is monotypic.

Rachipteron philopelum Thompson, 1964

Rachipteron philopelum Thompson, 1964; Rev. Biol. Trop., 12: 98-101; figs 1a-b (external morphology), 1c (operculum), 1d-e (penis), 1f (radula), 2 (shell).

TYPE LOCALITY — Seepage pools along the banks of the Rio Grande de Tárcoles, about 1/4 mile above the mouth of the river, Costa Rica (09°44’ N, 84°37’W). Holotype UMMZ 216478.

DISTRIBUTION RECORDS — COSTA RICA: known only from brackish streams along the Pacific coast of Costa Rica. In addition to the type locality the species is recorded from Quebrada Bomba Vieja at Boca de Barranca, Puntarenas Prov.

Pyrgulopsis patzcuarensis Pilsbry, 1891

Pyrgulopsis patzcuarensis Pilsbry, 1891; Nautilus, 5: 9 — Pilsbry, 1891; Proc. Acad. Nat. Sci. Phila., 43: 330; pl. 15, fig. 8.

Tryonia patzcuarensis (Pilsbry). Taylor, 1966; Veliger, 9: 197.

TYPE LOCALITY — Lake Patzcuaro, Michoacán, México. Holotype ANSP 61588.

DISTRIBUTION RECORDS — MICHOACÁN: known only from the type locality. Possibly extinct.

Family ASSIMINEIDAE H. Adams & A. Adams, 1856

Genus Assiminea Fleming, 1828

TYPE SPECIES — Assiminea grayana Fleming, 1828.

DISTRIBUTION — Tropical and sub-tropical regions of much of the world.

TAXONOMY — There are numerous species. Only five have been recorded from the New World. Two are brackish water inhabitants. Three occur in freshwater (Hershler, Liu & Lang, 2007), of which a single species is found in Mexico.

Assiminea cienegensis Hershler, Liu & Lang, 2007

Assiminea sp. Taylor, 1966; Veliger, 9: 208.

Assiminea pecos Taylor, 1987; Bull. New Mexico bur. mines and mineral res., 116: 8-9 (in part).

Assiminea cienegensis Hershler, Liu & Lang, 2007; Bydrobiologia, (579): 328-333; figs. 4, 6 (shell), figs. 7a, 7b (protoconch), figs. 7c, 7d (operculum), figs. 8-9 (anatomy), figs. 10a-f (radula).

TYPE LOCALITY — Southern portion of a spring-marsh complex just W of Mex. Hwy. 30, ca. 2.5 km N of Poza de la Becerra, Cuatro Cienegas Basin, Coahuila (ca. 26°53’ N, 102°08’ W). Holotype USNM 10714o2.

DISTRIBUTION — COAHUILA: known only from the Cuatro Cienegas Basin.


Superfamily VALVATOIDEA

Family VALVATIDAE Gray, 1840

DISTRIBUTION — Holarctic.

TAXONOMY — A single genus is recognized generally.

Genus Valvata Müller, 1774

Valvata O. F. Müller, 1774: 198 — Fischer and Crosse, 1891: 293-302 — Von Martens, 1899: 426. (Type species by original designation: Valvata crista Müller, 1774.

DISTRIBUTION — Holarctic in distribution.

TAXONOMY — Thirteen species occur in North America. Two species are known from México.

Valvata beltrami Contreras-Arquiet, 1993

Valvata beltrami Contreras-Arquiet, 1993; Publ. Biol., Univ. Auto. de Nuevo León, Supl., 1: 1-6.

TYPE LOCALITY — Manantiel Charco Azul, San Jose de Avilés, Aramberri, Nuevo León, México. Holotype USNM 860587.

DISTRIBUTION — NUEVO LEÓN: known only from the type locality, and from Manantiel La Prensa, 2 km N of the type locality.

Valvata humeralis humeralis Say, 1829

Valvata humeralis Say, 1829; New Harmony Disseminator of Useful Knowledge, II: 244 — Burch, 1989; Walkerana, 1: 81-82, fig. 25 (shell) — Pilsbry, 1903; Proc. Acad. Nat. Sci. Phila., 55: 778-779; pl. 52, fgs. 12, 12a (shell) — Hinkley, 1907; Nautilus, 21: 79.

Valvata humeralis Say (humerosa Say). Strebel, 1873: 33; pl. 4, fig. 42 (shell).

Valvata strebeli Fischer & Crosse, 1891: 304.

Valvata humeralis strebeli Fischer & Crosse — Von Martens, 1899; Biol. Centr. Amer., 427.

TYPE LOCALITY — Lakes around México City, Distrito Federal, México. Syntypes ANSP 1904 (H. B. Baker, 1965).

DISTRIBUTION — MEXICO. DISTRITO FEDERAL: Mexico City; Lago de Xochimilco (Pilsbry, 1903). Valvata humeralis humeralis is found from Montana south to Colorado and west to British Columbia and California (Burch 1989). Henderson (1929) contends that western U.S. records are based on Valvata humeralis californica Pilsbry, 1908, which most authors subsequent to 1908 recognize as a valid subspecies. Burch does not list V. h. californica. In México Valvata humeralis humeralis is known only from the type locality near Ciudad México, and from one locality in SAN LUIS POTOSI: Valles River near Valles (Hinkley, 1907).

Valvata humeralis pilsbryi Von Martens, 1899

Valvata humeralis Say. Pilsbry 1891; Proc. Acad. Nat. Sci. Phila., 43: 326.

Valvata humeralis var. pilsbryi Von Martens, 1899: 427.

Valvata humeralis var. patzcuaroensis Pilsbry, 1899; Proc. Acad. Nat. Sci. Phila., 51: 392.

TYPE LOCALITY — Lago de Patzcuaro, Michoacán, México. Holotype ANSP 77192a [H. B. Baker, 1965].

DISTRIBUTION — MICHOACÁN: known only from the type locality.