PALEONTOLOGY. 437 



S. Grieri Hall. 



S. macro. Hall. 



►S". macrothyris Hall. 



5". Manni Hall. 



.S. Marcyi Hall. 



5". Oweni Hall. 



.S. segmenta Hall. 



»S. varicosa Hall. 

 Spiriferina D'Orb. 



3". raricosta Conrad's sp. 

 Cyrtina Davidson. 



C. HamiltonicB Hall. 

 Meristella Hall. 



M. nasuta Conrad's sp. 



M. scitula Hall. 

 Nucleospira Hall. 



N. concinna Hall. v 



Atrypa Dalman. 



A. reticularis I,inn. 

 Rhynchoneua. Fischer. 



R. Billingsi Hall. 



R. Carolina Hall. 



R. Dotis Hall. 



R. Thetis Billings. 



R. ? raricosta Whitf. 

 Pentamereli,a Hall. 



P. arata Hall. 

 Terebratula Schlotheim. 



T. Sullivanti Hall. 

 Tropidoleptus Hall. 



T. carinatus Conrad. 



LAMELLIBRANCHIA TA. 



Avictjlopecten 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. 

 Mytiiarca 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. 



