Ferruginous Sand Formation. 291 



BACULITES. 



B. compressa. (Say.) PL IX, fig. I. This beautiful fossil was 

 described by Mr. Say in the American Journal of Science,* but 

 is now figured, for the first time, from a fine specimen in the posses- 

 sion of my friend, Jno. P. Wetherill, Esq. and brought from the Great 

 Bend of the Missouri river. Ahhough I have not been able to obtain 

 any details of the geology of this remote region, I have no hesitation 

 in placing the B. compressa in the series of ferruginous sand fossils. 



B. asper. (S. G. M.) Transversely suboval, with prominent lat- 

 eral nodes between the septa. From Alabama. 



SCAPHITES. 



S. reniformis. (S. G. M.) About an inch in length, with numer- 

 ous costse that bifurcate laterally. This species bears no resem- 

 blance to S. Cuvieri of this Synopsis, but is not very unlike S. stria- 

 tus, of the British chalk. 



NAUTILUS. 



JV. DeJcayi. (S. G. M.) PI. VIIT, fig. 4. This is the only spe- 

 cies hitherto found in our marls. It has been sometimes compared 

 to JV. expansus (Sowerby) but is much larger : it has also been con- 

 founded with the British JY. imperialis, to which, however, it bears 

 no other resemblance than all the species of this genus bear to each 

 other. I have much pleasure in dedicating this fossil to one of the 

 most zealous and intelligent of American naturalists. 



NUMMULITES. 



JV. MantelU. (S. G. M.) PL V, fig. 9. Flattened, thin, be- 

 coming sharp at the edge, and having a central pustuloid elevation. 

 Diameter from half an inch to an inch and a half. Innumerable in the 

 whitish, loose grained limestone near Claiborne, Alabama. I have 

 much pleasure in dedicadng this only known American species of 

 Nummulites, to one of the most zealous and successful cultivators of 

 geological science. 



SIMPLE AND SPIRAL UNIVALVES. 



PATELLA. 



P. tentorium. (S. G. M.) Compressed, circular, with sixty or 

 eighty delicate ribs ; diameter half an inch. This fossil has some 

 appearance of a shelly operculum, in wliich case it would belong to 



the genus Hipponix. 



. — . ^ 



* Vol. ii, p. 41. 



