300 RESEARCH IN CHINA. 



Po-SHAN. 



Spirifer bisulcalus Sowerby Produdus granulosus Phillips 



Spirifer duplicicosta Phillips Bellerophon hiulcus Sowerby ? 



Spirifer (Martinia) glaber Martin Loxonema walciodorense De Koninck 



Produdus semireliculatus Fleming Macrocheilus cf. intermedius De Koninck 



Produdus pundatus Sowerby Phymatifer pugilis Phillips 



Produdus humboldti d'Orbigny Naticopsis cf. globulina De Koninck 



Produdus sublavis De Koninck? Orthoceras sp. 



Produdus longispinus Sowerby Crinoid stems. 



From Hei-shan, in the same general region, the following closely related 

 fauna was obtained : 



Spirifer duplicicosta Phillips Produdus semireticulatus Fleming 



Spirifer bisulcalus Sowerby Produdus humboldti d'Orbigny 



Orthothetes crenistria Phillips Produdus longispinus Sowerby 



Produdus giganteus Martin Macrocheilus cf. intermedius De Koninck 



I see no reason for doubting the evidence which tends to correlate the 

 fauna from station 69 with that obtained by von Richthofen from Po-shan, 

 although they have very few species in common. Yet Freeh calls this horizon 

 Lower Carboniferous (Mountain limestone). My fauna presents but few 

 facts of real evidence upon this point, and I will dismiss everything except 

 the form which resembles Squamularia perplexa McChesney of the American 

 Coal Measures. As the result of a great many observations of my own and 

 some which are recorded in literature, I am tentatively accepting the generali- 

 zation that the early Carboniferous Reticulariae possess strong dental plates 

 and a median septum, while the later ones (Squamularia) were without any 

 sort of septal structures. More specifically, in our own section the Missis- 

 sippian forms possess internal plates and the Pennsylvanian ones do not. 

 Now, the Chinese fossils from station 69, so far as can be ascertained, are with- 

 out these internal structures. On this account especially, but also because 

 the fauna has more or less of a Pennsylvanian facies and lacks anything 

 distinctively Lower Carboniferous, I feel myself unable to correlate the Shan- 

 tung collection with our Mississippian. In this difference from Doctor Freeh 

 in regard to the age of this horizon I suppose it is possible that he may be 

 wrong and that the real age is Upper Carboniferous. In this connection the 

 fact should be noticed that the diagnostic form Proditctus giganteus appears 

 only in the lot collected at Hei-shan, and that it is represented only by a 

 fragment. Another point which may not be without significance is that these 

 faunas occur associated with coal beds. On the other hand, I very freely 

 admit that my own determination may be wrong. 



But there is still a third possibility that both determinations are right 

 and that we are merely using terms in different senses. If I understand 

 correctly, Freeh would place this horizon in the Mountain limestone of 

 European standards ; but while the Mountain limestone is usually correlated 

 with our Mississippian, it is possible that the upper beds of the Mountain 

 limestone may overlap upon our Pennsylvanian. On the other hand, in 

 applying the term "Upper Carboniferous" to this fauna I am using it not 



