THE NATURAL HISTORY SURVEY. 255 



of the aperture (or peristome) near the umbilicus; peristome 

 thickened, flat, reflected, the terminations joined by a thin 

 callus; outer lip sinuous, strongly arcuate at the upper portion; 

 interior of aperture pearly-white. 

 Length, 1.50; width, 0.75; aperture length, 0.50; width, 0.30 mill. Berry Lake. 



Animal: See generic description. 



Jaw: Arched, dorsal and ventral margins smooth; ante- 

 rior surface smooth or only slightly striated. 



Radula formula: ++}-++; central tooth long and nar- 

 row, expanded considerably at the lower outer corners; reflec- 

 tion small, short, heart-shaped, blunt, unicuspid; lateral teeth 

 a little longer than wide, reflection very low, serrated (Fig. 80). 

 The writer was unable to make out clearly the character of the 

 lateral teeth, but they appeared as indicated in the figure. 



Genitalia: Not examined. 



Distribution: United States west to Manitoba south to 

 Mexico. 



Geological distribution: Pleistocene; Loess. 



Fig. 



Radula of CARYCHIUM EXIGUUM Say. (Original.) c, central tooth; 

 1, lateral tooth. 



Habitat: Found plentifully under and about old logs, 

 sticks, twigs and vegetation in the vicinity of ponds and creeks. 

 Frequently found in wet moss. 



Remarks: This is quite a peculiar little species, distin- 

 guished by its light color and peculiar shell. It loves com- 

 pany, and when one is found dozens are always sure to reward 

 a patient search. The species is widely distributed in the area. 



io3. Carychium exile H. C. Lea, pi. xxvi, fig. 3. 



Carychium exile H. C. LEA, Am. Journ. Sci., 1 series, Vol. XLII, p. 



109, pi. i, fig. 5, 1841. 

 Carychium exile jamaicensis PILSBRY, Proc. Phil. Acad., p. 320, pi. 



xiv, figs. 15, 16, 1891. (Variety.) 



Shell: Similar to exiguum but differing in the following 

 particulars: the shell is elongated instead of cylindrical; there 



