TO GEOLOGY. 165 
older Pliocene, Maryland, and Mr Conrad two from York 
Town, Virginia, also the older Pliocene. 
GENUS NASSA. Lamarck. 
MN. cancellata. Plate 5. Fig. 170. 
Description. Shell turrited, cancellate; substance of 
the shell rather thin; spire elevated, not acutely pointed ; 
suture irregularly impressed; whorls nine, subangular 
above and furnished with a transverse furrow; mouth 
ovate ; columella but slightly thickened ; outer lip sub- 
crenate, striate within. 
Length .8, Breadth 7-20ths, of an inch. 
Observations. This finely ornamented Nassa has a 
strong resemblance to several recent species. It is can- 
cellate all over except at the very apex, where it is smooth 
and polished. 
I have observed but a single species of this genus among 
the shells received from Claiborne. I have not hesitated 
to separate this genus from Buccinum, (although Lamarck 
united them after having made the division) because they 
certainly form a very natural group. Cuvier* separates 
it, as M. de Blainvillet also does, into a subgenus. 
As neither the English nor French geologists have 
* Animal Kingdom, vol. 2, p. 374. | Manuel, &c. p. 408. 
