t-ij\ 20 P alxontologia Sinica Ser. B. 



China; (2) the cephalopods of Shih-tien' such as Vaginoceras {Endoceras) wahlenbergi 

 Foord, Orthoceras regulate Schl., Protocycloceras deprati Reed, etc. are also found in the 

 probably contemporaneous beds of the Neichiashan formation at Hupeh; (3) among 

 these collections from Hupeh described in the present paper, only a few forms namely 

 Cameroceras tenuiseptum Hall var. ellipticum Yu, Cameroceras hsiehi Y'a, etc. may be 

 compared with North American species, but the rest have characters in common 

 only with European types, though they are not generally conspecific with them. 



Prof. Grabau has suggested that the Sino -European Ordovician fauna was de- 

 rived from the Indian Ocean^ which invaded the southern part of the East Cathaysian 

 geosyncline in China on the one hand, and penetrated to western Europe by way of the 

 Himalayan trough on the other. He based this primarily on the apparent migration of 

 the graptolites in the Lower Ordovician period". According to Grabau's interpretation 

 we can understand why the Middle Ordovician cephalopods from Hupeh province 

 which was probably covered by the southern waters, are closely related to those from 

 South China as well as Europe, and are quite distinct from the North Chinese and 

 North American types which belong to another source, i. e. the Boreal province. 



One may argue that if the Indian Ocean was the home of the Sino-European 

 Ordovician faunas, why should the characteristic Vaginoceras (End.) wahlenbergi Foord, 

 which according to Foord's description^ was collected from the Orthoceras-Limestone 

 (referred by him to the Arenig) at typical locaUties in Sweden, Norway, Russia etc., 

 makes its first appearance in the Middle Ordovician beds of southern as well as central 

 China where the distance from the Indian Ocean is much nearer than that in the 

 western Europe. Now this question is easily answered if we have read over what is 

 called "Comparison of American and European Lower Ordovician formations" by Prof. 

 Grabaus in which he corrected the old misconception of the unity of the "Orthoceras 

 limestone". In Kinnekulle, Sweden the general Ordovician succession is as follows: 



1. Mr. S. S. Yoh had obtained many fossils, which are quite comparably to Brown's collection 

 from the Middle Ordovician beds of Shihtien, from the Shihtzupu shale at Shih-tzu-pu, 10 li north of 

 Tsung-yi district, Kuei-chow Province. But he did not find any cephalopod. (Bulletin of the Geol. 

 Surv. of China, No. 11, p. 33.). 



2. Grabau: China in the Ordovician Period. Bulletin of the Geological Society of the Nation- 

 al University, Peking, Vol. Ill, pp. 9-22. 



3. Grabau: Origin, Distribution, and Mode of Preservation of the Graptolites. Memoir of the 

 Institute of Geology, No. VII, pp. 1-52. National Research Institute of China. 



4. Foord: Catalogue of Fossil Cephalopoda, Pt. I., pp. 136-140. 



5. See Bulletin of the Geological Society of America, Vol. 27, pp. 555-622. 



