134 Mr. E. A. Smith on Arctic MoUusca. 



paler streaks here and there ; whorls 5^, verj convex, spirally 

 distinctly ridged, the ridges being alternately larger, longitudi- 

 nally rather coarsely striated by the lines of growth, and very 

 obsoletely plicated ; mouth irregularly ovate, large, occupy- 

 ing more than half the entire length of the shell, of the same 

 colour as the exterior, terminating inferiorly in a short, slightly 

 recurved canal ; columella oblique, scarcely arcuated, smooth, 

 shining, whitish towards the base ; epidermis thin, olivaceous, 

 and laminated slightly on the principal distinct incremental 

 lines or raised lirulse ; operculum circularly ovate, with the 

 nucleus rather central. 



Length 33 millims., diam. 17 ; aperture 19 millims.long and 

 11 wide. 



Hab. Dobbin Bay, 30 fms. {Hart). 



The dentition of the animal of this species closely resembles 

 that of Buccinum groenlandicum and Nep- 

 tunea antiqua, as represented by Tros- 

 chel's figures in his work ' Das Gebiss 

 der Schnecken,' vol. ii. pi. vi. 



The above description was already pre- '^ 

 pared under the supposition that the spe- 

 cimen before me was distinct from B. T* 

 Belckeri, when, through the kindness of 

 Dr. Gwyn Jeffreys, I was enabled to 

 compare it with the type of that species. 

 It is less elongated, has a rather shorter 

 spire ; and the body-whorl is more ven- , a muwi f 

 tricose. The columella also is less arcuate (v_^ C-— ~7 '^ILJ) 

 and more oblique, and the spiral ridges {A /^^^^^ r^. 

 and lines of growth are more pronounced. ^^^ ^ ^ vi. J) 

 The type does not display such regularity 

 in the alternation of large and small trans- 

 verse ridges as thfe variety. A specimen of this species from 

 Finmark, in the collection of Mr. Jeffreys, very closely re- 

 sembles the shell from Dobbin Bay. 



Like the rest of the genus this species is subject to great 

 variation. The type specimen is comparatively smooth and 

 without plications beneath the suture ; others are strongly 

 plicated, and have the spiral ridging much raised. 



Buccinum sericatum, Hancock, 



Ann. & Mag. Nat. Hist. 1846, vol. xviii. p. 328, pi. v, f. 6. 



Hah. Dobbin Bay, 30 fms. {Hart). 



The radula of this species is remarkable for the unequal 

 dentition of the side plates, one of which is a trifle the narrower 



Buccinum Belcheri. 



