CONTRIBUTIONS 

 TO THE 



CAMBRIAN FAUNAS OF NOR IH CHINA 



Y. C. SUN. 



INTRODUCTION. 



Since the important and extensive studies of Walcott on the Caralrian Faunas of 

 China, no worlv was done in the field until the systematic collection of Chinese fossils, in 

 connection with the detailed exploration and mapping, was undertaken by the Geological 

 Survey. In 1919 Mr. H. C. T'an of the Survey made a collection of Cambrian fossils 

 from the northern rim of the Kaiping Basin which proved of such interest on preliminary 

 study by Prof. Grabau, that it Avas decided to make a more detailed examination of the 

 Cambrian as well as other formations of this locality. Accordingly the Survey sent an 

 expedition to the Kaiping Jlasin, in charge of Prof. Grabau, and of this I Avas a member. 

 On our return, the Cambrian material was placed in my hands for study and description. 



In the same year, Dr. J. ( K Andersson studied the Sha-Kuo-Tun fP 'M '^ 

 deposits in west Fengtien, and brought back a collection of Upper Cambrian fossils from 

 this region, where the Upper Cambrian rests disconformably upon the Sinian rocks. 



In the spring of 1923, the National University Expedition, in charge of the 

 author, went to 'Sliantung to study the Cambrian stratigraphy of that province. I was 

 accompanied by several college students (C. C. Yang, S. T. Chang, C. C. Tien, 

 Y. T. Chao, K. iM. Wang, P. Tsai) who assisted me in measuring sections and making 

 collections of fossils. 



In the upper part of the Chaumitien limestone of Chau- Mi-Tien, we found a new 

 horizon containing many species of Ortltoceras and other cephalopods. Associated Avith 

 these are Ptychaspis, Eooriliis and the new genus Changia of the family Dikelocephalinx. 

 The cephalopods probably represent an invasion of an early Ordovician type of fauna 



