THE NATURAL HISTORY SURVEY. 



247 



the lower margin concave and the outer corners expanded; 

 reflection small, low, tricuspid, the center cusp reaching about 

 half way to the margin of the base of attachment, the side 

 cusps very small; lateral teeth almost as wide as long, bicus- 

 pid, the inner cusp long and wide, reaching below the base of 

 attachment, the outer cusp short and blunt; marginal teeth at 

 first a modification of the lateral teeth, the base of attachment 

 being wider than high and the inner cusp gradually shorten- 

 ing; as the margin is reached the teeth become eight-cuspid 

 (serrated) and are very wide and low ( Fig. 75). The cusps are 

 all provided with strong cutting points. There are about 90 

 rows of teeth. 



Genitalia: See generic description. 



Distribution ; North America, Europe and Asia; Point Bar- 

 row, Alaska. (Lehnert.) 



Geological distribution : Pleistocene; Loess. 



Habitat: Found plentifully under dead leaves and twigs, 



Fig. 75. 



Radula of COCHLICOPA LUBRICA Miiller. (Original.) c, central tooth; 

 1, first lateral; 11, third marginal; 18, eighth marginal; J, jaw. 



under decaying bark of fallen trees, in moss, etc., at the base 

 of very old trees. It prefers the open forest. 



Remarks: A species at once known by its cylindrical, 

 shining, glossy shell. The young shell of this species might 

 easily be mistaken for a small Helix; it is short and stumpy 

 and the thickened peristome, so characteristic of the adult, is 

 not developed. In many forms the edge of the lip of the 

 adult shell is colored reddish-brown, and there is a yellowish- 

 white line or band around the penultimate whorl, where the 

 liver shows through the shell. It is an interesting species in 

 captivity, the animal being very bold and readily crawling over 



