SIPIIO. 125 



S. PROPINQUUS, Alder. PI. 51, figs. 300, 301. 



Resembling S. gracilis in shape, but narrower, thinner, less 

 opaque, and somewhat more glossy, the whorls not so convex, 

 the outer lip not projecting so much and more contracted or 

 incurved above. Length, 1'75 inches. 



Great Britain, muddy and sandy ground in the coralline and 

 deep-water zones ; Norway ; Sweden ; Nova Scotia ? 



Jeffrej^s says, " The shell of the female is more tumid than 

 that of the male. Capsules solitary, and attached to the inside 

 of old bivalves ; they are hemispherical, and resemble those of 

 F. gracilis, but have a smaller and oval orifice ; the base is mar- 

 gined by a narrow membrane. Embryo the color of a pomegranate. 

 The smaller size and more delicate texture, finer and closer 

 sculpture, longer, turreted, and regularly tapering spire, deeper 

 suture, hispid epidermis, less abrupt curvature of the canal and 

 especially the symetrical apex will readily serve to discriminate 

 this from the last species." 



Mr, Verrill has obtained from the waters of Nova Scotia two 

 shells which are referred by Mr. Dall to this species after direct 

 comparison with authentic specimens thereof. 



N. Ebur, Kobelt, non Morch (fig, 301), described as a white, 

 polished variety, with more acute spire and less incurved canal, 

 was probably, as suggested by Morch, polished in the stomach of 

 a fish. 



S. TORTUOSUS, Reeve. PI. 51, figs. 302, 303. 



White, under a thick, olive epidermis. Length, 42 mill. 



f Arctic America; Norway. 



Var. TURRITA, Sars. Pl,/01, fig. 304. 



Smaller and thinner, more slender and almost cylindrical, with 



a larger spire. 



Shetland; Norway. 



Jeffreys considers this a variety of S. propinquus, Alder ; 

 which it may well be, but it is certainly more closely allied to 

 S* tortuosus if the shape of canal is a specific character : I think 

 all these differences of extreme^ doubtful persistence, and would 

 prefer to consider most of the so-called species mere modifications 

 of S. Islandicus. 



