THE NAUTILUS. 1 7 



near the angles of the hinge-line, hut in L. excavata there is no trace 

 of them, and the hinge of L. agassizii is too chalky to he certain 

 about their presence or absence. They are most distinct and prom- 

 inent in the young shell. L. agassizii was dredged by the U. S. 

 Fish Commission steamer Albatross, as were our specimens of L. 

 patagonica. 



THE SHELL-BEARING MOLLUSCA OF EHODE ISLAND. 



BT II. F. CARPENTER. 



The following species are additional to those hitherto described in 

 this series, and complete the list of known species from Rhode Island: 



214. Lucina filosa Stimpson. 



Lucina radula Gould, Inv. Mass., 1st ed., p. 69, 1840; Mighels, 

 Bost. Jour. Nat. Hist., iv, 318. 



Lucina contracta De Kay, Nat. Hist. N. Y., 1843. 



Lucina filosa Stimp., Shells of New Eng., 17, 1851. 



Shell white, thick, orbicular, moderately convex; hinge margin 

 straight; beaks small, pointed, projected over a small, indented, 

 smooth, lanceolate lunule. Exterior covered with remote, concen- 

 tric lamellar ridges, between which are round, thread-like striae. 

 Interior chalky-white, polished around the margins. Hinge straight, 

 with one cardinal tooth in the left valve and two small, diverging 

 teeth in the right valve. Length and height 2 inches: breadth, 

 1 inch. 



This is a rare, deep water shell and was not published in the de- 

 scription of the "Shell-Bearing Mollusca " of R. I. because it had 

 never been found and was not likely to be found in our waters; but 

 several specimens were dredged in Narragansett Bay, about two 

 years ago, by Prof. Herman C. Bumpus, then of Brown University, 

 in Providence, to whom I am indebted for the specimens now in my 

 collection. 



215. Physa gyrina Say. 



Shell heterostrophe, oblong ; whorls 5 to 6, terminating in an 

 acute apex ; suture slightly impressed ; aperture a little more than 

 half the length of the shell ; labium a little thickened on the inner 



