HELIX. 161 
“Testa obtecte perforata, conico-globosa, tenuis, cornea, oblique regulariter striata; spira conica; anfr. 5, 
planiusculis, ultimo obsolete angulato; apertura transverse lunato-ovali; peristom. simplice, vix expanso, 
margine columellari reflexo, carneo. 
“ Diam. 5, altit. 4 lin.” (123 and 10 millim.). 
Hab. Mexico (Hegewisch 1), 
T have not been able to find an authentic specimen of H. mexicana in any German 
collection, nor to recognize the species in any Mexican shell I have seen. It is said to 
be near H. indistincta, Fér., from Haiti, a species of the subgenus Plagioptycha, but to 
differ from it by the more elevated spire; in the description the callous thickening, 
characteristic of Plagioptycha, is not mentioned. 
Helix tenuicostata. 
Helix tenuicostata, Dunker, in Philippi’s Abbild. neuer Conch. ii. p. 6, t. 6. fig. 13 (1847) '; Pfr. 
Monogr. Helic. Vivent. i. p. 835”; in Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, Heliz, 
i. p. 224, no. 683, t. 109. figg. 14, 15°; Reeve, Conch. Icon. vii., Helix, t. 178. fig. 1228 * ; 
Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 298°. 
* Testa perforata, depresso-globosa, solidula, oblique costulato-striata, alba, rufo-multifasciata ; spira elevata, 
late conica; anfr. 44, convexiusculis, sensim accrescentibus, ultimo antice deflexo ; apertura lunato-ovali ; 
peristom. acuto, intus labiato, margine dextro subexpanso, columellari reflexo, adpresse dilatato, foramen 
fere tegente. 
“Diam. 64, alt. 4 lin.” (163 and 10 millim.). 
Hab. t MExico. 
This species is said to be near H. gilva, Fér., from Cuba, subgen. Polymita. It may 
perhaps be a variety of H. berlandieriana *, only the description of the sculpture does 
not agree; judging from the published figures, I am inclined to identify it with 
H. gilva. H. tenwicostata is not represented in Dunker’s collection, nor in the 
Museum of Berlin. 
Species erroneously attributed to Mexico. 
Helix indistincta. | 
Helix indistincta, var. 8, Pfr. Monogr. Helic. Vivent.i. p. 194°; in Martini & Chemnitz, Syst. 
Conch.-Cab. ed. 2, Helix, ii. p. 154°. 
Hab. Mexico (David ' *). 
This is a Haitian species, and Pfeiffer himself states (Monogr. Helic. Vivent. iii. 
p. 150) that the variety p is also found in Haiti. 
Helix mormonum. a — 
Helix mormonum, Pfr. P. Z.S. 1857, p. 109"; Monogr. Helic. Vivent. iv. p. 276°; Binney, Terr. 
air-breath. Moll. N. Am. iv. p. 15, t. 79. fig. 21°; Binney & Bland, Land and Fresh-water 
Shells of N. Am. i. p. 171, fig. 299°. 
BIOL. CENTR.-AMER., Terr. and Fluviat. Mollusca, April 1892. 21 
