NO. I 



CAMBRIAN FAUNAS OF EASTERN ASIA 



in the limestones referred to the Upper Cambrian where it has a con- 

 siderable vertical range ^ and wide geographic distribution. 



The absence of a true Dikelocephalus is to be noted, as the genus 

 is associated with Ptychaspis and Tsinania in the Upper Cambrian 

 of the interior portions of the North American continent. It is not 

 certainly known from the western or Cordilleran region. 



FAUNAL PROVINCES OF THE CAMBRIAN IN ASIA 

 Mr. F. R. Cowper Reed ' has given a summary of the geographic 

 distribution of the Cambrian formation in Asia, and called attention 

 to the probability that Freeh's " Pacific Zoogeographical province " 

 would need to be subdivided.' I find that while the Cambrian fauna 

 of the Pacific Province of eastern Asia has a strong generic relation- 

 ship with that of the Rocky Mountain area of western North Amer- 

 ica, yet in each area there is a group of genera that are not found 

 in the fauna of the other area. On this account it seems best to con- 

 sider the Rocky Mountain Province* as a subprovince distinct from 

 the Middle and Upper Cambrian of the eastern Asian subprovince 

 of the same periods. The Lower Cambrian Redlichia fauna of Asia 



^ Walcott, C. D. Smithsonian Misc. Coll., Vol. 53, Cambrian Geology and 

 Paleontology, No. S, 1908, Cambrian sections of the Cordilleran area, pp. 175, 

 177, 192, 204, 205. 



* Reed, F. R. C. Mem. Geol. Survey India, Palaeontologia Indica, ser. 15, 

 Vol. 7, 1910, No. I, The Cambrian fossils of Spiti, pp. 62-70. 



' Idem, p. 63. 



* Walcott, C. D. Bull. U. S. Geol. Survey No. 81, 1891, Correlation papers, 

 Cambrian, pp. 313-330, pi. i. 



