Geology 273 
eal 
from the Scymnus and Leemargus as the two latter present when com- 
Species on account of the strong bend backwards of the main point of 
the tooth, and the distinct and rather marked serration of the edges of 
the crown. Moreover, the inclination of the central point upon its 
basis gives these teeth a certain resemblance with those of Spinax and 
Centrophorus, and still more with Galeocerdo. The connexion of the 
teeth of the same row of the jaw with one another, was evidently the 
Same as in the Scymnus and Leemargus, as is plainly shown by the 
to the upper tertiaries. 
The Atlantic States have already yielded satisfactory indications of 
the presence of this genus during the tertiary period, on the eastern 
Coast of America, Now we receive from the collection of Mr. Blake 
from the Eocene of Europe, especially common in the Molasse of 
Switzerland, that were there not several specimens in the collection 
greeing with one another in every respect, and unitedly differing from 
in the Poisson Fossiles, al! the species formerly referred to the genus 
Carcharias have been ascertained to belong to the genus C rcharodon. 
pee discoveries in this field, therefore, could be of more interest than 
finding among the tertiaries of Ocoya cl es ee oe 
the edges serrated, especially near th giao 
are smooth and sharp. ‘These. diffe h of the 
r 
the 
