44 CRETACEOUS GROUP 



This species is immediately recognized by its tuber- 

 cles, which are unconnected with undulations. It was- 

 discovered by Mr. Nuttall, at Cahawba, Alabama, and 

 more recently by Mr. Conrad at Prairie Bluff, in that: 

 state. 



4. B. columna, (S. G. M.) pi. xix, fig. 8. 



Specific character. Transversely subovate, with numerous, 

 distant, arched ribs, which can be traced round the entire peri- 

 phery, but arc most distant at the sides. 



Diameter, half an inch. 



From Prairie Bluff, Alabama. Found by Mr. Conrad. 



5. B. carinatuSy (S. G. M.) pi. xiii, fig. 1. 



Specific character. Transversely subcuneiform, the siphun- 

 cular margin being distinctly carinated. Sides with distinct, 

 oblique, equidistant, arched ribs. 



From Prairie Bluff, Alabama, where it was found in 

 considerable numbers by Mr. Conrad. 



6. B. labyrinthicus, (S. G. M.) pi. xiii, fig. 10. 



Specific character. Shell with two series of distant nodes, 

 nearly parallel ; posterior series marginal, the anterior series in 

 the middle ; diameter subpentagonal ; back flattened ; anterior 

 side cuneiform; septa profoundly sinuous, crowded. 



Found by Mr. Conrad, at Prairie Bluff, Alabama. 



Ha MITES. 



1. H. arculus, (S. G. M.) pi. xv. fig. 1 and 2. 



Specific character. Transversely suboval, compressed, with 

 very distant, profoundly elevated, pyramidal nodes, and inter- 

 mediate smaller ones near the anterior edge ; nodes slightly 

 curved; septa close, and profoundly sinuous. 



