Vol I, 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 Actinoceras richthofeni, 

 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 

 hori/on is to be regarded as at the boundary-line 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 

 determined. 



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

 Lore n z and Freeh, is Orthis calligramma variety orthambonites, of the type figured by de 

 \Vrneuil 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-tno in northeastern Chihli. The 

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



CARBONIFEROUS FORMATION 



(Great hiatus and disconformity) 

 ORDOVICIAN FORMATION 



Liangchiashan formation 275m. 



Gray massive more or less dolomitic limestone with fbwiliferoua horizon 



(F3) 53 m. below the top 129m. 



Limestone conglomerate (intraformational) 1 m. 



Gray massive limestone 118 m. 



Conglomeratic limestone, grayish blue 1 m. 



Pule grayish limestone in thin layers 2fi in. 



Shihmunchai formation 155m. 



Interstratified sill 6 m. 



*). The presence in this limestone in Shantung of Dalmanella ct ttttudinaria and PlfftamboniUt tmcnu as 

 recorded by Crick, Lorenz and Freeh also suggests enrly Trenton, while Maclurea lognni recorded by I.orenz again suggests the 

 Black River, 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. 



