TO GEOLOGY. 115 
the last described, differing, however, in being less elevated 
and without strie. It has some resemblance to 4. mela- 
noides (Conrad), but has no striz. 
The genus .fcteon has been observed in England, where 
nine species have been described, as low as the Inferior 
Oolite ; two are from the London Clay, and two from the 
Crag. M. Deshayes’s Tables give eleven from the Tertiary 
period: being in all the three subdivided periods, Pliocene, 
Miocene and Eocene. In the Tertiary of Maryland, at St 
Mary’s, Mr Conrad has observed two, ovoides and mela- 
noides, described by him in vol. 6, Jour. Acad. Nat. Sci. 
FAMILY SCALARIANA. 
GENUS SCALARIA. Lamarck. 
S. planulata. Plate 4. Fig. 102. 
Description. Shell conical, closely ribbed, minutely and 
transversely striate between the ribs ; substance of the shell 
thick ; spire rather elevated ; ribs about twelve, rounded ; 
whorls 
, flattened, the last one only ribbed to the 
middle ; mouth round. 
Length .3, Breadth 3-20ths, of an inch. 
Observations. Having only a single specimen of this 
species, and that mutilated, Iam unable to give its charac- 
