374 THE CANADIAN NATURALIST. [Oct 



the centre and the outer edge ; outer margin sinuated opposite the 

 nucleus ; scar of lower surface correspondingly sinuated ; marginal 

 limb around the scar considerably thickened. 



Length, 1.54 ; breadth, 0.81 inch. These dimensions are those 

 of a specimen from Behring's Straits. 



Although B. ciliatum is the most distinct and well marked form 

 in the genus, it is by no means a common species, and, when 

 found, has been frequently referred to other quite different species, 

 for want of attention to its peculiar characters, although these 

 were originally very well described by Otho Fabricius. The 

 appressed form of the shell, narrow, somewhat canaliculated aper- 

 ture, and the tooth on the columella are its prominent characters. 

 Hancock speaks of the tooth in the description of his B. cyaneum. 

 and Middendorff has it distinctly marked in his figure of tenebrosum ; 

 so that there can be no doubt with regard to the shell meant by 

 those authors. 



On the other hand the name ciliatum has been applied to a very 

 different species, the Humphrey sianum of Bennett, by Dr. Gould 

 and others. 



We have the true B. ciliatum in the Smithsonian Collection, 

 from Greenland, where it was originally found by 0. Fabricius. 

 Hancock reports it from Davis' Straits ; a specimen from the 

 Newfoundland Banks is in the collection of Dr. Gould ; and I have 

 received it from the coast of Nova Scotia through the kindness of 

 my friend, Mr. J. B. Willis of Halifax. I have it also from 

 Behring's Straits and the Arctic Sea north of it, collected by Capt. 

 John Bodgers of the North Pacific Expedition ; and specimens from 

 the mouth of McKenzie's Biver were sent to the Institution by 

 Mr. B. W. McFarlane. I am not aware that it has ever been 

 found in a fossil state. 



BUCCINUM PLECTRUM, 110V. Sp. 



Shell rather large and thin, elongated ; spire produced ; sutures 

 less deep than in B. tenue ; whorls seven or eight, regularly convex, 

 or slightly appressed, less gibbous or shouldered at the sutures than 

 in B. tenue, and not carinated. Longitudinal folds very numerous, 

 about nineteen, as broad as their interspaces, and most prominent 

 near the suture ; — they are curved in a somewhat sigmoid form, and 

 are sometimes, though rarely, interrupted, or have an intervening- 

 fold about the middle of the whorl. The striation of the surface 



