ORDOVICIAN FOSSILS FROM NORTH CHINA. 



BY 



A. W. GRABAU. 



INTRODUCTION. 



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

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

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

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

 hmestones in north China, which carry many elements of the Carhoniferous 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 are now known to Ije of 

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

 Richthofen 's monumental work, published in 1911, described two specimens of Adinoceras, 

 (.1. richthofeni 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 Actinocerits from Canada which was figured 1)}^ Bar- 

 rande under the name Adinoceras ridiarJsoni Stokes. Freeh also described a fragmentary 

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

 Raphistoma leqxdlatenmi Koken which occurs in the Chasmops-Kalk (Upper Ordovician) 

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

 Trochoceras sp, from Shantung, in the British Museum, together with Dahnanella cf. 

 teshcdinariO' (p. 8). 



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

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



