184 BUCCINUM. 



It might be taken for a thin and delicate form of B. nndafam, 

 bnt is easily distinguished by the number and straightness of the 

 longitudinal plications of the spire-whorls, the more numerous 

 and sharply cut transverse ridges and the wider mouth. Occurs 

 in thi> pleistocene beds of Moutreal, 



B. TENUE, Gray. PL 76, fig. 327. 



Whorls convex; with twenty-five to thirty longitudinal ribs, 

 sometimes interpolated about the middle of the body-whorl ; no 

 prominent revolving sculpture, but merely crowded minute striae, 

 sometimes obsolete. Length, 1-75 to. 2*5 inches. 



Greenland, southwards to Otilf of St. Lawrence ; Nora Zembla ; 



Lapland; BeJirinrfs Straits. 



Tliis is a circumpolar species, possessing the well-known facies 

 of sucli shells ; its occurrence southwards in the Gulf of St. Law- 

 rence is rare and in deep water. It is a pleistocene fossil in 

 various localities from Canada northwards. The well-expressed, 

 very numerous, curved and partially duplicating ribs and the 

 almost total absence of transverse sculpture are its distinguish- 

 ing characters. B. scalar if or me., Heck, is possibly a synonym, 

 although it is also referred to Siplio Kroyeri.^ Moller, Besides 

 the typical form, Middendortf mentious a forma elatior, in which 

 the ribs lend towards evanescence. B. tortuosum, Reeve, is con- 

 sidered a monstrosity of this species by Stimpson, but I tliink it 

 more i)robable that it has that relation to Fusus (Sipho) Kroijeri., 

 Moller. 



B. i'LECTRiJ_M, Stimpson. 



Shell rathei' large, thin, elongated, wliorls less convex than in 

 B. tenue, with about nineteen curved longitudinal folds, and deep 

 cut primary revolving gi'ooves, witli depr(!ssed intervening ridges. 



Length 2*23 to 2-5 inches, dinin. 1-2 inches. 



Arctic Ocean, nuvth of Beliring' s Straits ; 



30 to 30 fathoms. 



It may be described in brief language by saying that it has 

 nearly the form and jjlaits of B. tenue, with a striation of the 

 ylaciale type. It evidently approaches nearest to tenue, but 

 besides the ditference iu the striation, tiie much greater regularity 

 of tlie longitudinal plaits will serve to distinguish it. I have 

 among a number of fossil Bncciuums kindly loaned by Dr. 



