2 RESEARCH IN CHINA. 



Director of the Royal Geological and Paleontological Institute and Museum 

 at Berlin, who very kindly had photographs made for me of all the specimens 

 illustrated by Doctor Dames that could be identified in the collections. 



Through the courtesy of Dr. Wilhelm Deecke, of the Geological Institute 

 of the University of Freiburg, I have had the opportunity of studying most of 

 the specimens from China used for illustration by Dr. Th. Lorenz [1906]. 

 This enabled me to make identifications that otherwise would have been very 

 difficult, owing to the fragmentary character of the specimens illustrating 

 the trilobites. 



The chief results obtained from the study of the Chinese collections are 

 the discovery of portions of the upper part of the Lower Cambrian fauna and 

 a great development of a Middle Cambrian fauna of the same general char- 

 acter as that of the Cordilleran Province of western North America ; also an 

 Upper Cambrian fauna comparable with that of the Cordilleran Province 

 and the Upper Mississippi Province of the United States. The fauna of the 

 upper zone of the Lower Cambrian was found to be of the same general type 

 as that of the Cambrian fauna of the Salt Range of India, and we were thus 

 enabled definitely to locate the faunal horizons in India which have hereto- 

 fore been referred to Upper Cambrian and post-Cambrian formations. 



Another important discover} 7 was that of the occurrence in the Middle 

 Cambrian of China of a fauna comparable with that of the Middle Cambrian 

 of Mount Stephen, British Columbia, and the southern extension of the 

 same fauna in the Middle Cambrian of Idaho, Utah, and Nevada in the 

 United States. 



The determination of the age of the Man-t'o shales affords the data by 

 which to fix the period of Cambrian time in which the Cambrian sea trans- 

 gressed over eastern and southeastern Asia, and shows that it was somewhat 

 later than the transgression in the Siberian area now occupied by the basins 

 of the Lena and Yenesei rivers. 



A noteworthy addition to the knowledge of the Cambrian faunas was 

 the discovery for the first time of a true cephalopod in a fauna referred to the 

 Upper Cambrian. This is illustrated by a species of Cyrtoceras, which occurs 

 in the lower part of the Ch'au-mi-tien limestone. Other details will be found 

 in the discussion of the subfaunas and their stratigraphic and geographic 

 distribution. 



From the study of the collections described in this memoir I anticipate 

 that a large and varied fauna will soon be found in the Cambrian formations 

 of China. What we now have is the result of hurried and superficial col- 

 lecting. Persistent search by trained collectors will undoubtedly give mate- 

 rial comparable in extent and beauty with that of America and Europe, and 

 add many unique genera and species to the great Cambrian fauna. 



CHARLES D. WALCOTT. 



April 26, 1913. 



