1889.] NATURAL SCIENCES OF PHILADELPHIA. 81 



NEW AND LITTLE-KNOWN AMERICAN MOLLUSCS. No. 1. 

 BY HENRY A. PILSBRY. 



Under the above title I propose to describe and figure the 

 species of American mollusks, either new to science or imperfectly 

 understood, accumulating from time to time in the collection of this 

 Academy. In this first contribution are presented the results of my 

 study of a number of* forms received from various collectors and 

 localities in the Southern States, Mexico, etc. 



Holospira elizabethse Pilsbry. PI. Ill, figs. 1 to 5. 



Shell imperforated, cylindrical, becoming narrower toward the 

 base, rather solid, white, opaque, the apex tiesh-colored ; whorls 17 

 to 22, slightly convex, slightly, irregularly striate near the sutures, 

 nearly smooth in the middle, the last whorl costulate-striate, flesh- 

 tinted beneath, narrower than the preceding whorls, its last half 

 rounded, not carinated beneath, produced forward, expanded toward 

 the peristome ; aperture round, truncate above ; peristome expanded, 

 thin, continuous, its upper margin slightly sinuous. Spire wider 

 above; terminating in a short flesh-colored cone ; apex obtuse, the 

 apical whorl rather large and prominent. Internal column wide 

 above, tapering toward the base, hollow, marked by regularly spaced 

 longitudinal fold-like ridges. 



Alt. 21, diam. maj. 5, of penult, whorl 4 mill. 



Alt. 15, diam. maj. 5j of penult, whorl 4] mill. 



Alt. 16, diam. maj. 5} of penult, whorl 4 mill. 



Aperture : alt. 3, diam. 3 mill. 



Village of Amula, between Tixtla and Chilapa, State of Guerrero, 

 S. \V. Mexico. 



Although the proportions of length to diameter are so variable, 

 the aperture is nearly the same size in all of the specimens. The 

 species is decidedly larger than any described Holospira. Its near- 

 est allies seem to be H. Gealii H. Ad., H. imbricata Mart., H.micro- 

 stowa Crosse and Fischer ; but I need not here compare these 

 species with H. elizabethce, for they can be separated at a glance. 



1 am indebted to Mr. Herbert H. Smith, the well-known entomologist, 



for specimens. 



The animal is whitish, the whole surface reticulated and granose, 

 the granules elongated, brown. The foot is about 6 mill, in length, 



2 mill, broad. The mantle is about central. It is very timid Ac- 



