LIMNAA. 89 
3. LIMN/ZA CASTA, Lea. 
Plate 16, figs. 3, 4, 5. 
Shell subfusiform, narrow, whorls very ob- 
lique, flattened, thin, imperforate ; whorls five, 
spire narrow, pointed ; aperture narrow-ovate, 
effuse below. Light horn color. 
Length 15, diam. 8 mill. 
Rhode Island, Ohio, Georgia. 
This shell is much narrower and more ob- 
lique than columella. Fig. 3 represents a spe- 
cimen from Georgia, which I consider typical 
in its form; fig. 4 is an outline of the type of 
Dr. Lea’s LZ. strigosa, and fig. 5 represents L. 
coarctata, Lea, the latter founded on a mon- 
strosity of frequent occurrence in all the spe- 
cies of Limnea,—namely, an angulated instead 
of a rounded periphery. 
(63) 
