New Fresh-Water Nhells. 325 
shell, sub-ovate acute above, angle of its plane with 
the axis of the shell about 15°, of its length with 
the axis about 10°; labrum not thickened internal- 
ly ; fold of the dittila distinct, but not very large ; 
umbilicus rather small. 
` Length, .48 inch ; breadth, .22 inch. ’ 
Cabinets.of the Bost. Soc. Nat. Hist. ; ; of Middle- 
bury College ; of Dr. A. A. Gould, of Bisoi of J. 
G. Anthony, of Cincinnati; and my own. 
Habitat and station. This species was found in 
considerable numbers at Shoreham, Vt., on the shore 
of Lake Champlain, clinging to rocks and stones. 
Remarks. This species must resemble L. acuta, 
Lea, of which, however, I have not seen a specimen. 
That shell, in a very brief description, is said to be 
delicate, smooth, and dark brown, while this is rath- 
er strong, striate, and of avery pale horn color, in 
living specimens, like the weathered shells of kin- 
dred species. "The figure represents the columella of 
the acuta as intruding upon the aperture, which is 
not the case with this shell. 
LIMNÆA UMBILICATA. 
Plate III. Fig. 14. 
L. testi fuscA, ovata, striis transversis tenuibus, volventibus tenuis- 
simis; anfractibus quinque, convexis; spirå subacutà ; apertura ova- 
tà, labro intus fusco-marginato, puniceo-albo submarginato ; columellà 
lat? reflexA, obsoleté plicatà ; umbilico subamplo, baud profundo. 
Shell rather strong, brown, ovate, with slight strice 
of growth, and more slight numerous, irregular, re- 
volving, impressed lines ; whorls five, convex ; suture 
deeply impressed ; spire two-fifths of the length of 
