156 



once from every other described American species, are more 

 apparent on the middle of the body whorL These are quite 

 coarse, and placed at irregular intervals; — on some specimens 

 scarcely discernible. The aperture is unlike that of any other 

 of our species ; being correctly egg-shaped, — it is nearest in form 

 to that of S. campestris, but is less expanded. The parietal wall 

 of the aperture is unusually horizontal. 



In general aspect it resembles somewhat S. vermeta, but is 

 distinguished from that shell by its more oval shape, and the 

 greater convexity of the whorls. It is the heaviest American 

 species. 



HELIX INTERCISA. 



Testa solidissiraa, luteo-cinerea, apice rufa, globoso-eonica ; 

 spira brevis ; sutura impressa ; anfractus quinque, convexiusculi, 

 lineis parallelis volvenlibus, valde demissis, strias incrementales 

 distinctas intercidentibus notati ; anfr. ultimus globosus, supra 

 peripheriam fascia union, rufa obscurissima ornatus ; apertura 

 maxime obliqua, forma equi calcei, rotundata; labrum albo-cine- 

 reum, incrassatum, subtus reflexiusculum, subunidentatum, umbil- 

 icum totum tegens ; marginibus approximati:^', callo interjunctis. 



SYNOXYMS AND IlEFEREXCES. 



Helix Nlckliniana. Lea. var. Binney Terrestrial Molhisks, II. p. 120, 

 III. pi. VI. f. 1. Ico7i in medio posita. 



DESCRIPTIOX. 



Animal wot observed. 



Sliell globose-conic, with five slightly-rounded whorls ; spire 

 little elevated ; suture distinct ; upon the body whorl a dark 

 revolving band, hardly discernible ; aperture very oblique, shape 

 of a horseshoe ; peristome thickened, heavy, dirty white, slightly 

 reflected at the umbilicus, which it entirely conceals near its 

 junction with the columella, furnished with a tooth-like process, 

 the extremities connected by a heavy ash-colored callus, which is 

 spread more lightly over the whole parietal wall ; epidermis 

 grayish yellow, apex rufous. The striae of growth are very 

 numerous and distinct, crossed by numerous, regular, revolving 

 lines, so deeply impressed as to entirely separate them into small 

 sections ; thus the whole surface of the shell is divided into minute, 



