218 



much distorted to be used for satisfactory comparison, and his description 

 is brief.* 



Compared. Prof. \W. C. Brogger figures a species (Bellerophon Norvegicus], from a 



corresponding horizon in Norway.! It is a little smaller, the outer whorl 

 expands more rapidly and is free for half of its length ; it is not deeply 

 notched like our species ; though differing in these respects, it has a 

 striation similar to the Canadian species, only in place of being sharply 

 curved back at the dorsum, the striae curve forward in crossing that line. 



Bellerophon 

 Bretonensis. 



Compared. 



BELLEROPHON BRETONENSIS. PI. xviii, 4 a-d. 



Bull. Nat. Hist. Soc. of N. Brunswick, vol. iv, p. 409, pi. xviii, figs. 4 a-d, 







Shell of about two or more whorls, the outer whorl large and moder- 

 ately expanded. Orifice somewhat enlarged and strongly emarginate on 

 the dorsal side by a sharp V-shaped sinus. Sides of the opening strongly 

 arched upward between the dorsal and ventral sides. No distinct keel. 



Sculpture. The surface is diversified with numerous rounded ridges 

 concentric to the umbo, with flat spaces between ; there is a sharp, nar- 

 row furrow along the crest of each ridge ; the ridges near the orifice are 

 sharper and more crowded than farther back on the whorl ; here there 

 are about three in the space of 2 mm., but towards the mouth about four. 

 The fine sculpturing of the surface appears to be a minute granulation. 



Size. Length from the inner part of the last whorl to the lateral edge 

 of the lip, 20 mm. Width across the shell from the dorsum to the inner 

 part of the last whorl, 12 mm. 



Horizon and locality. Fine gray shale of Assise C, 3 c 2 at McLeod 

 brook, Boisdale, N.S. 



The characters of this shell are obscured by flattening in the shale. The 

 umbo appears to be excentric, and it resembles B. (Elerti, Bergeron, of 

 the Lower Ordovician of the Montagne Noire in Southern France, J but 

 has fewer whorls. Similarly to that species, the ridges on the shell are 

 more distant from each other on the upper part of the main whorl than 

 towards the aperture. I could not detect any flattened ridge along the 

 keel of the dorsum. 



This shell is distinct from B. arfonensis, Salter, by the sharp angula- 

 tion at the dorsal line, and the striae that cross it are angulated, not arched. 



* Quart. Jour. Geol. Soc., London, vol. xxix, No. 113, p. 50, pi. iii, figs. 30-32. 

 t Memoir cited, p. 53, pi. x, figs. 15, 15a, 156. 



JEtnde geologique du Massif Ancien situe au sud du Plateau Central, J. Bergeron, 

 Paris, 1889, p. 343, pi. iv, figs. 10 and 11. 



