34:6 0. Holtedahl — Upper Cambrian Fauna 



China (Research in China, 3, Washington, 1913). Yet the 

 size of the pygidia seems to be somewhat larger in com- 

 parison with the associated cephalons than is general in 

 Anomocarella, in this respect resembling Asaphiscus 

 Meek. Besides these, there are two large fragmented 

 cephalons that do not seem to differ from Illcenus, a type 

 of trilobite that we do not expect in the Cambrian. A 

 nearly smooth pygidinm with axis only faintly indicated 

 may belong to the genns Symphysurus Goldfuss, or to 

 Tsinania Walcott. 



As to the age of the fossils from the sonthern locality, 

 there seems to be no reason to donbt that the presence of 

 Huenella indicates Upper Cambrian time. The genns is 

 especially characteristic of this epoch and is not known to 

 occur in the Ordovician. The two American forms that 

 come nearest to the species from Novaya Zemlya both 

 occur in the Upper Cambrian, and there is nothing in the 

 character of the rest of the fauna that nullifies such a con- 

 clusion. That we are dealing with a time very close to 

 the base of the Ordovician is indicated by the types of 

 orthoids, especially the reversed type pointing to Ordo- 

 vician relations. 



In the fossils found in the light colored sandstone, this 

 faunal relation to post-Cambrian (Ordovician) strata is 

 still more emphasized by the occurrence of a species of 

 Illcenus. Yet the dominating trilobite s are such that we 

 should not "expect the time to be younger than Ozarkian. 



Even this preliminary study of the Novaya Zemlya fos- 

 sils shows with great distinctness that the faunas in their 

 general expression are highly different from those of the 

 Upper Cambrian (and basal Ordovician) of the British- 

 Scandinavian region and of the North American Atlantic 

 area as well. They are essentially like those from the 

 Cordilleran and Interior regions of North America, and 

 from China. It seems evident that in Novaya Zemlya we 

 are dealing with Upper Cambrian strata and fossils that 

 belonged to a large, world-wide ocean, compared with 

 which the North European Upper Cambrian sea with its 

 relatively poor and monotonous trilobite fauna has a very 

 local dispersion. The dominance of the "Pacific" realm 

 of Upper Cambrian time, as compared with the restricted 

 "Atlantic" one, now becomes still more accentuated, since 

 the great Arctic region evidently belongs to the former. 



