Two New Species of North American IlelicidcB. 171 



species above named. II. demissa Binney seems to be related, 

 but is barely perforate, not so much depressed, and instead of 

 the slight, equally distributed inner thickening of the lip, has a 

 copious basal deposit or callosity. II. placentula Shuttl. is also 

 closely allied, but has two more whorls; is more depressed 

 (" arctispiral"), and more polished. Shuttleworth, in his descrip- 

 tion of the II. placentula, points out its relations to H. demissa 

 Binney, and says that it is at once " distinguished from it by 

 the absence of the opake white basal callus," which is found 

 in the latter. He describes II. placentula as having the peri- 

 stome simple and acute, with no mention of internal thickening, 

 which, had it been present, could hardly have escaped his prac- 

 tised eye. 



2. Helix foarhigera. 



Testa imperforata, acute carinata, lenticular!, tenuiuscula, corneo-fusca, 

 epidermide superne striis asperata, qua? ad suturam et carinam in ciliis 

 productae sunt ; basi convexa, ; spira, convexiuscula ; anfractibus 5^ sub- 

 planis, ultimo subito paululum deflexo ; apertura perobliqua, transversa, 

 auriformi, dente modico linguiformi oblique intrante in toto pariete aper- 

 turali coarctata; peristomate callosa, lnargiiiibus incrassatis et reflexius- 

 culis, basali subsinuato, integro. 



Shell imperforate, sharply carinate, rather thin, dark horn- 

 colored, or brown ; the upper surface has the epidermis raised 

 into acute strias, which, at the suture and carina, are produced 

 into short bristles ; these epidermidal striae are sometimes seen 

 beneath, but less distinctly, being often obsolete in the mature 

 shell; basal surface convex, but indented in the umbilical 

 region ; spire slightly convex, whorls five and a half, rather 

 fiat, last one suddenly but slightly deflected ; aperture very 

 oblique, transverse, ear-shaped, narrowed by a rather slender 

 tongue-shaped tooth, which extends nearly across the whole 

 width of the aperture; peristome callous, margins slightly but 



