306 helicwidje. 



Genus SCHASICHEILA, Shuttleworth. 



Operculum thin, testaceous, with an intraniarginal rih, 

 the inner margin straight, with a thickened lamella inferiorly 

 produced into a point. 



Shell glohose-conical, covered with a fimbriated epidermis 

 disposed in spiral lines, last whorl rather flattened at the 

 base, the umbilical region callous and deeply impressed; 

 aperture semi -circular ; peristome continuous, deeply incised 

 above at the insertion, the superior margin beyond the in- 

 cision produced into a wing-like process. 



Syti. Helicina, part, Menke. 



Ex. S. alata, Menke, pi. 87, fig. 6. Operculum, S. 

 alata, fig. 0, a, 6, b. 



The notch or incision of the outer lip where it joins the 

 body-whorl is the principal character of this genus. The 

 species are few in number. 



Species of Schasicheila. 



alata, Mke. pannucea, Morel. 



Nicoleti, Shuttl. 



Genus ALCADIA, Gray. 



Operculum non-spiral, rather solid, semi-oval, the base 

 furnished with a dentiform process. 



Shell heliciform, turbinately sub-globose or somewhat 

 depressed, generally pilose, callous at the base around the 

 straight, somewhat flattened columella ; aperture triangu- 

 larly semi-oval ; peristome more or less expanded, with a 



