CONCHOLOGIA CESTRICA. 77 
Animal, foot large, greatly produced beyond the 
rostrum, narrow, and rounded behind, truncated in 
front; rostrum short; tentacles broader, and shorter, 
than in Melantho; the right one, in the male, only 
one-third the length of the left; operculum with a sub- 
spiral nucleus. 
L. subcarinata, SAY. 
Paludina subcarinata, Say, Nich. Encyc., 3d Amer. 
Edit., 1819. 
Shell, whorls 3 or 4, reticulated, with * eae 
striae, and wrinkles; apex truncate, and Fig. 157. 
re-entering; suture deeply impressed; 
aperture oval, more than half the length 
of the shell; carina, two, or three, or 
absent; color brownish- green; within 
bluish-white. H.15, W. 9, mill. 
Station, Schuylkill River, Chester County ; abundant. 

Lingual Dentition ul DL, sub- Operculum of DL. sub= 
carinata. — [W. G. B.] carinata.—|W. G. B.] 
Fig, 158. Fig, 159, 
Oss. — Our shell differs, somewhat, from the same 
species found in Western waters. 
Family VALVATID&A. 
Animal of V. tricarinata, — [W. G. B.] 
ce 160, 
Shell, spiral, turbinate, or discoid; peristome entire. 
hak 
