scHucHEET.] TABLES OF NORTH AMERICAN SPECIES. 



Table IV, — Ordovician Brachiopoda — Continued. 



35 



Species. 



Triplecia nucleus Hall 



Triplocia (?) radiata "Whitlield 



Triplecia ulrichi Winchell and Schuchert 



Zy gospira cincinuatiensis Meek 



Zygospira concentrica Ulrich 



Zygospira defleeta (Hall) 



Zygospira exigua (Hall) 



Zygospira kentuckiensis James 



Zygospira modesta Hall 



Zygospira nicoletti "Winchell and Schuchert 



Zygospira putilla Hall and Clarke 



Zygospira recurvirostra (Hall) 



Zygospira safford i Winchell and Schuchert 



Number of Ordovician species, 319. 



Number of species in each division 



Number of species common to the Calciferous and the other 



divisions 



Number of species common to the Chazy and the other 



divisions 



Number of sj)ecies common to the Trenton and the other 



divisions 



Number of species common to the Cincinnati and the other 



divisions 



Species common to the Ordovician and Silurian systems, 5. 

 Number of species passing from each division into the 



Silurian 



Eoordovician. 



Calcifer- 

 ous. 



Chazy. 



63 



Mesoordo- 

 vician. 



Trenton, 



Black River, 



Birdseye. 



26 



T 

 T 



T 

 T 



Neoordo- 

 vician. 



128 



27 



Cincin- 

 nati, 

 Utica. 



Ci 

 Ci 

 Ci 



Ci 



U,Ci 



Ci 



136 



27 



