Ferruginous Sand Formation. 291 
BACULITES. 
-B. compressa. (Say. ) Pl. IX, fig. 1. 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. Although 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 coste that bifurcate laterally. This species bears no resem- 
blance to S. Cuviert of this Synopsis, but is not very unlike S. stria- 
tus, of the British chalk. 
: NAUTILUS. 
WN. Dekayi. (S.G.M.) Pi. VIII, fig. 4. This is the only spe- 
cies hitherto found in our marls. It has been sometimes compared 
to V. expansus (Sowerby) but is much larger : it has also been con- 
founded with the British JV. imperialis, to which, however, it bears 
no other resemblance than all the species of this genus bear to each ’ 
other. Thave much pleasure in dedicating this fossil to one of the 
most zealous and intelligent of American naturalists. 
NUMMULITES. ; 
LN. Mantel. (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 dedicating 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 which case it would belong to 
* Vol. ii, p. 41. 
