I20 The Ottawa Naturalist. [September 



Canada. This specimen, which is also imperfect at both ends, 

 is about a foot in length, and seven inches and three quarters in 

 breadth at the larger end. 



In the fall of 1897, however, a specimen from East Selkirk, 

 collected by the late Professor J. H. Panton in 1884 and belong- 

 ing to the Provincial Museum at Winnipeg, which is obviously- 

 referable to this species, was lent to the writer by Mr. J. P. 

 Robertson, at the suggestion of Mr. Tyrrell. This fossil is a badly 

 preserved cast of the interiorof the shell in a slab of building stone, 

 and only the ventral surface is exposed. It is of interest as being 

 much the largest specimen of the species that has yet been found 

 andashavingaconsiderable portion of the body chamberpreserved. 

 As measured along the middle of the exposed surface longitu- 

 dinally, its length is twenty-three inches, the septate portion being 

 twelve inches in length and the non- septate eleven. Its maxi- 

 mum diameter or breadth is seven inches and three quarters at 

 the smaller end, and nine inches and a quarter at the larger. 

 About twenty-eight septa can be counted in the septate portion, 

 and they are from a quarter of an inch to a half an inch apart 

 at the surface. The specimen is slightly imperfect at both ends 

 and must have been more than two feet in length when entire. 



According to Professor J. M. Clarke (op. cit. p. 793) the 

 OrtJioceras zipldas, O. Jiastatum and O. servile, of Billings, are 

 referable to Hyatt's genus Tripteroceras. To these may be added, 

 as Canadian representatives, the present species and possibly 

 O. semiplanatuni, nobis. 



Cyrtoceras Quebecense. (Sp. nov) 



Shell elongate conical, increasing very slowly in thickness 

 and not much curved ; dorsum slightly compressed, venter and 

 sides rounded. Siphuncle large, cylindrical, dorsal and mar- 

 ginal ; septa apparently rather closely approximated. 



Length of the only specimen collected, which is imperfect 

 at both ends, about seventy-five millimetres, or three inches ; 

 thickness of the same about eleven mm. at the smaller end, and 

 nearly thirty at the larger. 



