104 PLIOCENE MOLLUSCA. 



Beinarls. — Mr. Friele and other recent authorities regard the B. tumidvlvm of 

 Prof. G. 0. Sars as a variety of B. liydroj^hcnmm, with which it agrees generally 

 except that it has a shorter spire and more tumid whorls. 



Posselt has described another and comparatively short form from Greenland 

 which attains a maximum length of 80 ram. as var. iv/mido^a . He says it comes 

 fairly near to B. tumidulum, but is much larger. 



Among my many specimens of Buccinum from Oakley there is one, now 

 figured, which nearly corresponds with some Recent shells I have received from 

 Prof. Nordgaard as B. hijdroplianum, although the whorls of the former are some- 

 what less tumid. It appears to be intermediate between the typical form of that 

 species and B. tumidulum; Dr. Sparre Schneider, however, to whom I have 

 submitted my fossil, considers it should be referred to the latter, but as a variety 

 of B. hj/drojjhauum. 



Mr. Friele states that both forms occur at medium depths in all parts of the 

 Arctic Ocean. 



Buccinum tenue, Gray. Plate VIII, figs. 10, 11. 



1839. Buccinum tenue, G-ray, Zool. Beechey's Voyage, p. 128, pi. xxxvi, fig'. 19. 

 1846. Buccinum tenue, Reeve, Conch. Icon., vol. iii (Buccinum), pi. iv, fig. 27. 

 1858. Buccinum tenue, Kilster, Martini uud Chemnitz, Conch. Cab., vol. iii (Buccinum), p. 77, pi. xiv, 



fig. 7. 

 1872. Buccinum temic, J. W. Dawson, Canadian Natur. (n. s.), vol. vi, p. 397, pi. vii, fig. 5. 

 1883. Buccinum tenue, Kobelt, Martini und Chemnitz, Conch. Cab., ed. 2, pt. iii (Buccinum), \>. 39, 



pi. ixxxi, figs. 4, 5. 

 1887. Buccinum tenue, Kobelt, Icon, schalentrag. europ. Meeresconch., vol.i, p. 110, pi. xx, figs. 3, 4. 

 1912. Buccinum tenue, Dauteenberg et Fischer, Camp. Scient. Pr. Monaco, vol. xxxvii (MoUusques), 



p. 137, pi. vi, figs. 10, 11. 



Specific Characters. — Shell ovato-fusiform, conical, thin ; whorls 7, convex, the 

 last about five-eighths the total length ; ornamented by numerous flexuous longi- 

 tudinal plications, which tend to die out towards the base of the shell, and b}^ fine 

 inconspicuous spiral stride ; spire elongate ; apex rather blunt ; suture deep or 

 well-marked ; mouth oval, obtusely-angulate above ; outer lip thin ; pillar exca- 

 vated ; canal very short, open. 



Dimensions. — L. 38 — 55 mm. B. 20 — 30 mm. 



Distribution. — Recent : circumpolar : Nova Zembla, Spitzbergen, Kara Sea, 

 Franz Joseph Land, Iceland, Arctic coasts of European and Asiatic Russia ; 

 Behring Sea, Icy Cape ; Greenland, Labrador, North American coast to Halifax, 

 (N.S.). 



Fossil : Waltonian Crag : Little Oakley. Butleyan : Butley. 

 Pleistocene : Riviere du Loup (Canada), Greenland, Labrador, 

 Yenisei. 



