1865.] REVIEW OF THE NORTHERN BUCCINUMS. 3(37 



B. glaclale and B. groenlandicum. From the former it differs in 

 its thin structure, shouldered whorls, and narrower aperture. It 

 is larger and broader than B. groenlandicum, and the aperture is 

 comparatively larger and more narrowed anteriorly than in that 

 shell, which, moreover, never has shouldered whorls. 



The characters given by Gray for the distinction of this species 

 from B. glaclale do not hold good. That species often has whorls 

 • deeply striated and closely plicated :> as occurs in B. polar e. 



Btjccinum gr(ENLAndicum Hancock. 



Buccinum groenlandicum Hancock, An. and Mag. Nat. Hist. [1], xviii 

 (1846), 329 ; v, 8, 9. Reeve, Conch. Icon,, iii (1847), Buc, xiv, 118. 



Tritonium Hancocki Moerch, in Rink's " Greenland,," Tillaeg. (1857), 

 Aftryk, 84. 



Buccinum undatum Dawson, Can. Nat., ii (1857), 415. 



Shell rather small, very thin, moderately elongated ; spire conical. 

 Whorls six or seven, not shouldered, regularly convex except near 

 the suture, where they are flattened ; carinas of the body-whorl 

 two to four, that commencing at the upper angle of the aperture 

 being the principal one, but less prominent than in B. glaclale. 

 Longitudinal folds often obsolete ; when present about fifteen in 

 number on the body-whorl, most conspicuous at the middle, where 

 they often form tubercles on intersecting the carinas. The spiral 

 grooves, both primary and secondary, are much like those of B. 

 polare, but are less regular, the ridges being of unequal width. 

 Aperture short, less than one half as long as the shell, and broad, 

 broadest above the middle. Outer lip not sinuated. Columellar 

 lip deeply incurved above, as in B. polare. Periostraca thin, 

 smooth. 



Length, 1.75; breadth, 0.93 inch. Dimensions taken from a 

 fossil specimen from Montreal. 



The species was originally described by Mr. Hancock from 

 specimens dredged in Davis's Straits. It has since been found 

 quite abundantly in the pleistocene beds at Montreal by Prof. 

 Dawson. The fossil specimens appear to be all of the smooth 

 variety, in which the folds are nearly obsolete and the carinas not 

 tuberculated. 



It is very closely allied to B. polare. The chief differences are 

 mentioned under that species, but it maybe added that the groov- 

 ing is usually shallower and less distinct in B. groenlandicum than 

 in B. polare. It differs from B. glaclale in being smaller, much 



