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.) pl. xix, fig. 8. 
Specific character. 'Transversely subovate, with numerous, 
distant, arched ribs, which can be traced round the entire peri- 
phery, but are most distant at the sides. 
Diameter, half. an inch. 
From Prairie Bluff, Alabama. Found by Mr. Conrad. 
5. B. carinatus, (S. G. M.) pl. 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.) pl. xin, 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. 
HAMITES. 
1. H. arculus, (S. G. M.) pl. 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 stighaly 
curved; septa close, and profoundly sinuous. 

7 
a 
