56 RESEARCH IN CHINA. 



The absence of a true Dikelocephahis is to be noted, as the genus is asso- 

 ciated with Ptychaspis and Ill<znurns 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 [1910, pp. 62-70] has given a summary of the 

 geographic distribution of the Cambrian formations in Asia, and called 

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

 would need to be subdivided [Reed, 1910, p. 63]. I find that while the Cam- 

 brian fauna of the Pacific Province of eastern Asia has a strong generic 

 relationship with that of the Rocky Mountain area of eastern North America, 

 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 consider the Rocky Moun- 

 tain Province 1 as a subprovince distinct from the Middle and Upper Cam- 

 brian of the eastern Asian subprovince of the same periods. The Lower 

 Cambrian Redlichia fauna of Asia is so distinct that there is no probability 

 of its having lived in the same province with the Mesonacida? fauna of North 

 America. The North American Middle Cambrian fauna is distinctive in 

 having the brachiopod genus Nisusia Walcott and the trilobitic genera Karlia 

 Walcott, Ogygopsis Walcott, Burlingia Walcott, Zacanthoides Walcott, Oryc- 

 tocara Walcott, and Neolenns Matthew. 



The Chinese Middle Cambrian fauna has in its upper portion a few genera 

 not known from the North American fauna. These include, as described in 

 this memoir, Damesella, Blackwelderia, Teinistion, Stephanocare, Drepannra, 

 Shantungia, and Liostracina. The fauna containing the genera mentioned, 

 like that of the genera listed above from North America, belongs to a local 

 fauna that did not obtain a distribution outside of the limited area in which 

 it lived. It could not in either case have developed in the communicating 

 seas in which the greater world-wide and typical fauna of the Middle 

 Cambrian lived. 



The Upper Cambrian fauna of China, as now known, is essentially the 

 same in its generic aspect with that of western North America. This is 

 discussed in the section on The Larger Faunal Horizons [pp. 49-56]. 



A comparison of the faunas in the four local areas of the Cambrian in 

 Asia shows the presence of three provinces: 



1. Shan-tung Province (including Manchuria and Shan-si sub- 



province;. 



2. Punjab Province (including Yun-nan area). 



3. Siberian Province. 



'Walcott, 1891*, pp. 313-330, plate i. 



