OF THE UNITED STATES. 33 



Nautilus. 



1. N. Dekayi, (S. G. M.) pi. viii. fig. 4, and pi. xiii, 

 fig. 4. 



Specific character. — Shell very ventricose, with numerous 

 undulated, transverse striae ; aperture laterally and profoundly 

 expanded. 



From the marls of Monmouth and Burlington counties, 

 New Jersey. This is the only species hitherto found in 

 our marls. It has been sometimes compared to N. ex- 

 pansus, (Sowerby,) but is much larger: it has also been 

 confounded with the British N. imperialism to which, 

 however, it bears no other resemblance than all the spe- 

 cies of this genus bear to each other. I have much plea- 

 sure in dedicating this fossil to my friend Dr. Dekay, one 

 of the most zealous and intelligent of American natu- 

 ralists. 



Mr. Read has found fragments near Long-branch, 

 N. J., which when entire could have been little short of 

 eight inches in diameter. The casts so abundant at Prairie 

 Bluff, Alabama, (pi. xiii. fi^. 4,) are rounder and less 

 expanded at the mouth, than those from New Jersey, and 

 may possibly be distinct ; if so, I propose for it the name 

 of N. perlatus. 



2. N. Alabamemis, (S. G. M.) PI. 18, fig. 3. 



Specific character. — Shell suboval, compressed ; septae pro- 

 foundly sinuous; siphuncle very large. Length 10 inches; 

 height 9 inches ; greatest diameter 4j inches. 



From the newer cretaceous rock, near Claiborne, Ala- 

 bama. 



E 



