32 



fifth of iiii inch. Very abundant in ponds and other 

 waters. May Ix; easily known by the quadrate ap- 

 pearance of the wliirls, its round aperture, etc. 



VAI.VATA SI.X'I.KA, Say. 



This shell differs from the former si)eci(^s in being 

 smaller, and is without the carinated whirls. Found 

 in the same localities as the preceding species, but not 

 so abundant! \'. 



FAMILY VIVlPARIDiE. 



CJK.'MS VIVBI"VKA, Lam. 



This family is numerously represented in all our 

 rivers. The animals are sluggish in their habits. Tliev 

 inhabit muddy bottoms, or among the vegetation found 

 in our waters. Their food is veg(!tal)l(\ but not invari- 

 ably, as they have been found feeding on decayed aninuil 

 matt(n'. Many of the species are viviparous. I have 

 taken V. contectoides in the fall of the year, with the 

 ovaries full of the }■ oung, the shells showing distinctly 

 three of the bands peculitir to this species. The fool 

 of the animal is provided with an opercle which closes 

 the aperture when its owner withdraws into the shell. 

 Tn tlu; spring they deposit their young in the mud. 

 The shells are turrited. For ])urposes of study, I keep 

 a few species alive on my ]n'emises. 



VBVBPAKA co:v'ri:c:x<>ii>i-:s, v{. g. Binney. 



Shell large, globose, has live whirls, which are finely 



striated; peristome acute and continuous, tinged on 



the inner margin with a dark line ; ap(^rture subcircular ; 



{jolor brownish horn. The body whirl has four reddish 



