PALEONTOLOGY. 437 



►S. Grieri Hall. 



S. macra Hall. 



S. macrothyris Hall. 



S. Manni Hall. 



5". Marcyi Hall. 



S. Oweni Hall. 



.S. seg?nenta Hall. 



►S. varicosa Hall. 

 Spiriferina D'Orb. 



6". raricosta Conrad's sp. 

 Cyrtina Davidson. 



C. HamiltonicB Hall. 

 Meristeixa Hall. 



M. nasuta Conrad's sp. 



M. scitula Hall. 

 Nucleospira Hall. 



N. co7ici?ina Hall. 

 Atrypa Dalman. 



A. reticularis Linn. 

 Rhynchonella Fischer. 



R. Billingsi Hall. 



R. Carolina Hall. 



R. Dotis Hall. 



R. Thetis Billings. 



R. ? raricosta Whitf. 

 Pentamerella Hall. 



P. arata Hall. 

 Terebratula Schlotheim. 



T. Sullivanti Hall. 

 Tropidoleptus Hall. 



T. cari?iatus Conrad. 



LAMELLIBRANCHIA TA. 



Aviculopecten McCoy. 



A. crassicostatus H. and W. 

 A. parilis Conrad. 

 Pterinea Goldf. 



P. flabella Conrad? The specimens referred to this species 

 are very doubtfully identified. They are large, coarse 

 forms, very unlike any of those in the higher beds. 

 Myttlarca H. and W. 



M. ponderosa H. and W. 

 M. percarinata Whitf. 

 Conocardium Brown. 



C. trigonale Hall. C. Ohioense Meek, is the young of the 

 above. 



