Vol J. Grabau — Ordovician Fossils from North China. (i) 9 



the early Trenton beds of the central and eastern United States and Canada. Although 

 no species can be said to be absolutely identical, (except perhaps Adinoceras rieUhofmi, 

 with which is identified a specimen figured by Barrande from Canada*) still the majority 

 are representatives of species occurring in the American early Upper Ordovician forma- 

 tions, and indeed, in some cases these Chinese species are hardly more than geographical 

 varieties of the American forms. As such they indicate a very close correspondence of 

 horizons. The presence in our Chinese fauna, of forms closely analogous to species found 

 in the Stones River or upper Middle Ordovician of North America, indicates that the 

 horizon is to be regarded as at the boundary-Hne between Middle and Upper Ordovician. 

 Thus it is quite safe to correlate the Actinoceras horizon essentially with the Black River 

 formation of North America. How much of the underlying series of limestones represents 

 Middle Ordovician and what part is of Early Ordovician age, cannot at present be 

 deterrnined. 



The only European form I have noted in addition to those recorded by Crick, 

 Lorenz and Freeh, is Orthis callig rarama variety orthambonites, of the type figured by de 

 Verneuil from Russia. 



LOWER ORDOVICIAN. 



Undoubted Lower Ordovician fossils were discovered by Dr. F. F. Matthieu in 

 the Shi-mun-chai region northwest of Ching-wang-tao in northeastern Chihli. Tlie 

 stratigraphic succession here is as follows according to Dr. Matthieu.**) 



CARBONIFEROUS FORMATION 



(Great hiatus and disconformity) 

 ORDOVICIAN FORMATION 



Liang chiaahan formntion 275 m.' 



Gray massive more or less dolomitic limestone with fossiliferons horizon 



(F3) 63 m. below the top 129 m. 



Limestone conglomerate (intraforraational) 1 m. 



Gray massive limestone 118 m. 



Conglomeratic limestone, grayish blue 1 m. 



Pale grayish limestone in thin layers 2fi m. 



Shihmunchai forviation 155 m. 



Iiiterstratified sill 6 m. 



*). The presence in this limestone in Shantung of Dcdmandla at testitdinaria and Plectambonites sericeus as 

 recorded by Crick, Lorenz and Freeh also suggests early Trenton, while Mndurca logani recorded by Lorenz again suggests the 

 Black Biver, being known from that horizon in Canada as well as from Europe. 



**). The stratigraphy of this region will be more fully discussed by Dr. Matthieu in a forthcoming Bulletin of 

 the Survey. 



