CANADIAN PERIOD. 57 



The only specimen contained in the collections is the one figured on 

 Plate III. It has the appeai'ance of being slightly curved, as shown in 

 figure 5 c, which, if natural, of course removes it from the genus OrtJioce- 

 ras; but, as the specimen has been a little compressed at one end, it is 

 thought the curvature is due to that cause alone. If originally straight, as 

 it is thought to have been, it properly belongs to the subgenus Camaroceras 

 of Conrad, as is shown by the large peripheral siphuncle. 



Numerous annulated species of OrtJioceras have been published, but 

 the one here described possesses characteristics that seem to clearly distin- 

 guish it from them all. Compared with 0. xndclirum BaiTande, it differs in 

 having sinuated instead of direct annulations, an oval instead of a circular 

 transverse section, and in having a larger siphuncle, which is also peripheral 

 instead of central. From 0. annulatum Sowerby, as figured and described 

 by Barrande (not Endoceras anmdatum Hall), it differs in its proportionally 

 naiTOwer annulations as compared with the interspaces, its oval instead of 

 circular or nearly circular transverse section, and in its larger and periphe- 

 ral instead of central sijohuncle. From 0. dulce BaiTande, it diff'ers in its oval 

 nstead of cu'cular transverse section, and in its larger siphuncle, which is 

 also peripheral instead of central. From 0. undulostriatum Hall, it differs in 

 the course of its sinuous annulations, which both species possess, and in its 

 much larger and peripheral instead of central siphuncle. With 0. furtiviim 

 Billings from the Calciferous formation of Canada, it is closely related in 

 the character, size, and position of the siphuncle, but differs in its oval 

 instead of circular transverse section, and also in the direction and character 

 of the annulations. 



Position and locality. — Strata of the age of the Quebec group of Canada ; 

 Fish Spring, House range, Utah. 



Family CYRTOCEllATID^. 



Genus CYETOCEEAS Goldfuss, 1833. 



Cyrtoceras (?) 



Among the collections from strata of the age of the Quebec group, at 

 Fish Spring, House range, Utah, there is a specimen of Cyrtoceras, too 

 imperfect for specific characterization, but which resembles in general aspect 



