

366 



Review of the Neio York 



Fig. 3 occurs also in the hills at Cincinnati. Fig. 6 is, to all 

 appearance, the same as the Caradoc fossil of the same name rep- 



Murch 



If so, it is one of the 

 few species whose absolute identity on both sides of the Atlantic 



can be established. 



A Pleurotomaria, considered the same as fig. 2, has also been 

 found both in Iowa and Ohio. Here are some of the bivalves of 

 the Trenton limestone. 



CO 



o 



cu 



c 



s 



i 



S 



CO 



10 







5 



« 





•52 



O 



CM 



<N. 



PS 



^ 



CO 



05 



S 



o 

 S 



a 



CO 



kd 





ft. 



22 



© 



« 



s 



£h 





co 



2 

 c3 r-> - 



Ph 



0) 



CO 



CO 



8 







CQ 



CO 



The true & sericea is a Caradoc fossil ; if this be identical with 

 it, then there is another point of specific identity established . e- 

 tween the American and English fossils. A fossil closely alue 



