106 .. Couthouy’s New Species of Mollusca 
one being the largest; a distinct callus, in old specimens, 
covers a small portion of the body-whorl, whose colu- 
mellar extremity is bounded by a slight ridge. Shell 
covered with a thin, light olivaceous epidermis. 
Oszservations. This shell, which was found in 
considerable numbers, in various parts of our outer 
Bay, varies materially in its outward appearance, owing 
to the different disposition of the longitudinal strie. In 
some instances these are so fine as to cover the shell with 
an uniform reticulation, while in others, strongly marked 
folds sive it a rugose or even cancellated appearance, 
especially the superior portion of the body-whorl. 
Some of these latter varieties resemble externally the 
young of Nassa obsoléta, Sav, except in coloration. Im- 
mature specimens have the aspect of Fasciolarie. I 
have never found it with the animal in, but always ten- 
anted by a species of Pagurus. It is more analogous to 
. C. australis, SowEn., than to any other of the genus 
with which I am acquainted. 
Fusus HARPULARIUS. 
Plate I. fig. 10. 
F. testà fusiformi, turrità, fulvo-lutescente; anfractibus superné 
anra costis obliquis numerosis instructis, transversé tenuissimé 
striatis; aperturà obovata, labro levi, caudà per-brevi. 
Long. eleven twentieths, diam. of last whorl five 
twentieths, of an inch. 
Habitat waters of Mass. Bay. 
Cabinet of Boston Soc. Nat. History. 
Descrretion. Shell oblong, fusiform, turreted, color 
yellowish-brown, whorls six to eight, convex, slightly 
angular superiorly, and planulated at the suture, which 
is clearly defined; they are traversed by numerous, 
