124 GENUS ANCYLUS. [October. 



orbicular; lip much thickened, reflected^ white, distant 

 from the umbilicus; umbilicus large, exhibiting the volu- 

 tions. 



Breadth less than one tenth of an inch. 



Found under the bark of a decaying oak; is readily- 

 distinguishable from other species by its small size and 

 conspicuous lip. 



3. H. lahyrinthica, ^S'/ze'// conic, dark reddish-brown, 

 body lighter; -whorls five or six, with conspicuous, eleva- 

 ted, equidistant, obtuse lines across, forming grooves be- 

 tween them; apex obtuse; lip reflected, rounded; pillar 

 lip with a large, lamelliform, elongated tooth, which ap- 

 pears to revolve wnthin the shell parallel to the suture, a 

 smaller raised line revolves nearer to the base within the 

 shell, but becomes obsolete before it arrives at the pillar 

 lip; umbilicus rather large. 



Breadth one tenth of an inch. 



Found on fungus in decaying wood; this shell is re- 

 markable for the two, much elevated lines, which revolve 

 within the shell upon the penultimate whorl, the upper 

 one larger and terminating at the aperture very conspicu- 

 ously, and resembling a tooth. 



Genus ANCYLUS. Geoff. Latr. 



Shell conic, not spiral, concave beneath, above with a 

 simple apex. Animal with the eyes placed at the inner 

 base of the tentacula. 



Obs, This genus has been by writers confounded 

 with the Patellae. The European species are Patella la- 

 custris SiXidJluviatilis of Linne. 



