ORDOYICIAN FOSSILS FROM NORTH CHINA. 



BY 



A. W. GJIABAU, 



INTRODUCTION. 



i 



In his classical work on China, Ferdinand von Richthofen classified the great 

 limestone formations which underlie the coal-bearing series of north China as "Kohlen- 

 kalk " and referred them to the Carboniferous Limestone of Europe. In this he was not 

 altogether wrong, for we now recognize the existence of Lower Carboniferous (Dinantian) 

 limestones in north China, which carry many elements of the Carboniferous Limestone 

 fauna of western Europe. 



The greater part of the limestone series here under consideration was expressly 

 excluded by v. Richthofen from his Sinian System which comprised the Cambrian and 

 older rocks. It and a part of the rocks included in the Sinian arc now known to be of 

 Ordovician age, as was indeed recognized by Freeh, who in the fifth volume of v. 

 Kichthofen's monumental work, published in 1911, described two specimens of Actinoceras, 

 (.1. riflttliofeni Freeh) collected by von Richthofen in Manchuria, and correctly referred 

 them to the Upper Ordovician. Freeh further recognized that this form was similar to, 

 or even identical with, a species of Actinoceras from Canada which was figured by Bar- 

 rande under the name Actinoceras richardsoni Stokes. Freeh also described a fragmentary 

 gastropod collected by von Richthofen in the same strata, and referred it tentatively to 

 H'lpltixtomtt mjuilaterum Koken which occurs in the Chasmops-Kalk (Upper Ordovician) 

 of western Europe. He also notes the occurrence of specimens of Actinoceras sp. and 

 Tfochoceras sp, from Shantung, in the British Museum, together with Dalmanella cf. 

 testudinaria (p. 8). 



Previous to the appearance of Freeh's monograph, G. C. Crick (1903) had 

 described and figured several specimens of Actinoceras obtained by the Rev. Samuel 



