CERITHIOPSIS. 387 



straight, or a little recurved, narrow, deep, and partly closed over 

 by the continued lips. Length, one inch ; breadtli, three fifths of 

 an inch ; divergence, sixty degrees. 



Found sparingly on the shores of Buzzard's Bay, Nantucket, and 

 Martha's Vineyard. According to Mr. Say, it is abundant on the 

 Southern coast. It is the only species known on the coast of the 

 United States, and, as a species, is peculiar on account of the pro- 

 longation of its canal. 



Mr. Sowerby regards it as identical with R. muriciformis, Brod., 

 from Western Columl)ia. The alliance is very close, but ours is a 

 much more delicate shell. At any rate, Mr. Say's description was 

 published ten years before that of Mr. Broderip. 



[Animal : tube extends beyond the canal ; foot light yellow ; 

 head and tentacles nearly white, siphon also ; the whorls with 

 white dots and mottlings ; same at all ages ; operculum chestnut. 



Oemis CERITHIOPSIS, Forbes. 1849. 



Shell elongated, turreted ; aperture short, oblong, oblique, ter- 

 minating in front by a short, recurved canal. 



Cerithiopsis Emersonii. 



Fig. 180. 



Shell long-conical, chestnut colored ; whorls seventeen, flat, each encircled with 

 three series of granules ; canal less than half the length of the aperture. 



Ceritklum Emersonii, Adams, Bost. Journ. Nat. Hist. ii. 284, pi. 4, fig. 10. — Gould, Inv. 



Isted. 27.'j, fig. 180. 

 Cerithiopsis Emersonii, Stimpson, Check Lists, 5. 



Shell small, conical, elongated, glossy, reddish-brown, with a reg- 

 ularly granulated surface ; whorls sixteen or seventeen, 

 flattened, with a revolving series of bead-like granules at ^'s-^^- 

 the upper and lower margins of each, and another interven- 

 ing one, but nearer to the upper than to the lower series, 

 and less prominent, commencing at ten or twelve whorls 

 from the summit, and becoming more distinct as it ap- 

 proaches the base ; in each series the granules are con- 

 nected by a rather narrow, but elevated revolving line, 

 nearly as high as the granules ; they are also connected 

 in a similar manner in a longitudinal direction ; posterior edge of 



