382 MURICID.E. 



up the spire ; covered with a dense yellowish-brown epidermis, 

 bristling with stiff, curved hairs along the lines of growth, and at 

 regular intervals corresponding with the revolving lines of tlie 

 shell ; aperture ovate, three fourths the length of the shell, the 

 outer lip simple, sharp, and arched ; the inner margin concave and 

 twisted as it turns out to form the canal, smooth and enamelled ; 

 within, brightly polished, variously shaded with chestnut and fawn 

 color ; operculum small for the shell, oval, the apex at the lower 

 extremity, its elements coarse, strengthened on the inner side by 

 a varnished deposit. Ordinary length, six inches ; breadth, three 

 inches. 



Found about Nantucket, Martha's Vineyard, Buzzard's and Nar- 

 ragansctt Bays. It is set down, in all the works I have seen, as an 

 inhabitant of the arctic seas and Canada. But Cape Cod is proba- 

 bly its northernmost limit ; at least, I have never heard of it farther 

 north. I believe, too, that it does not extend far south. Alive at 

 Oysterville (^Haskell) ; Fort Macon, Georgia (^Covper'). 



It seems superfluous to be minute in the description of a shell 

 which would at once be recognized, when we have said that it is a 

 large, pear-shaped shell, with its peculiar channel at the suture, and 

 each whorl crowned with a beaded circlet. It is subject, however, 

 to considerable variations. It varies in color from light orange to 

 livid-brown. In thickness, also, there is great diversity. In the 

 old shells, the nodules, which are so regular in the young, are worn 

 off, and they seldom exhibit more than vestiges of the bristled epi- 

 dermis. The largest specimen I have seen is seven inches in length. 

 Kiener, like his predecessors, has associated two shells under the 

 same name, which are certainly distinct, and probably come from 

 different quarters of the globe. Which should be held as the 

 M. canaUcnlatus of Linn£eus, must remain uncertain, since the es- 

 sential character of his species is, a canal intervening between 

 the whorls at the suture (" qinxl anfractus in spira non contigui 

 sunt, scd canali distantes''''), a character which belongs to both 

 species. Gualter and Davila evidently had reference to our shell 

 alone. 



The ova are contained in membranous cases, about the size and 

 thickness of a cent (of IS-il). Great numbers of these arc united 

 together in a parallel position, about one fourth of an inch apart, by 

 a ligamentous thong attached to their edge, so as often to form 

 strings a yard in length, gradually diminishing in size from one 

 end to the other. They are represented in " Ellis's Corallines," 



