i6 



asked for errors in the specific or even generic determination of certain fossils 

 described in this paper. It may well be said that these fossils might better 

 have been excluded from the present study ; but often on such imperfect 

 specimens depends the fate of a formation of considerable extent and con- 

 siderable thickness at least so far its geological age is concerned, and it is 

 the duty of one who studies fossils to attempt as close an approximation to 

 the truth as is possible in order to help other geologists to study the strati- 

 graphical sequence in the field. 



As stated already above, a part of the present paper is devoted to a 

 brief statement of previous knowledge concerning the stratigraphy and 

 palaeontology of China, and the presentation of certain geological problems 

 requiring further research. Some of the geological results obtained by the 

 present study deserve special mention here, though they will be treated at 

 length in the following chapters. 



First of all, the discovery of a Coscinocyathus in the Ki-sin-ling lime- 

 stone of Willis and Blackwelder developed along the middle course of the 

 Yang-tse-kiang, in a horizon some 20C-500 m. above its very base, 

 is convincing testimoney as to the Cambrian age of the most part of the 

 limestone complex and suggests the possibility of its lower part being older 

 than any Cambrian rocks known elsewhere. At the same time the Lower 

 Cambrian age of the Nan-tou tillite underlying the Ki-sin-ling limestone at 

 Nan-tou seems by no means sure. 



The Ordovician age of the uppermost part of the Ki-sin-ling limestone 

 and the lower part of the underlying Sin-tan shale finds confirmation in the 

 discovery by Noda of many Ordovician fossils from two new localities in the 

 same district. Also Usui found there Ordovician fossiliferous beds con- 

 formably overlaid by basal-Gotlandian fossiliferous beds which themselves 

 underly Lower Permian limestones. The occurrence of basal-Gotlandian 

 beds in close association with Ordovician rocks seems to be the general rule 

 in Southern China. 



The limestones exposed along the I-chang gorge represent the upper 

 part of the Ki-sin-ling limestone of Willis and Blackwelder, and are not the 



