^58 
FOSSIL TURTLES 
water or marine sub-genera. The opinion of 
M. Cuvier is decisive as to the existence of an 
emys in these deposits ; and, from the details we 
shall now offer, that of a marine turtle is more 
than problematical. 
Ckelonicp, or Marine Turtles. — Ribs with a 
smooth surface, of nearly an equal width through- 
out, with pointed, striated extremities, and marked 
with impressions of scales *, portions of a smooth 
osseous border ; and sternal plates with radiated or 
dentated margins, are the remains which we pro- 
pose to refer to this subgenus. 
Some examples possess the striated projecting 
extremities, so characteristic of the ribs of the 
chelonice ; but as they are not connected with an 
osseous margin, they might be supposed to belong 
to the trionyx. From this division of turtles they 
are, however, separated by the smooth surface and 
the impressions of scales.* Of this species we 
have specimens of the pointed extremities of two 
ribs, which, from the form of the portion of the 
osseous border adhering to them, are probably the 
first and second ribs of the left side ; also the 
* Mr. Clift, our first comparative anatomist, the Curator of the 
Museum of the Royal College of Surgeons, obliged me by comparing 
this specimen with the recent skeletons in the Museum, and stated that 
it resembled the third rib of Testudo imbricata. 
Burtin {OryctograjMc de Bruxelles') figures the extremity of a rib 
very like this fossil ; and as M. Cuvier has referred the turtles of Mels- 
broeck to the Emydes, we at first entertained doubts whether our 
appropriation of this specimen to the chelo7ii<e were correct. Mr. Clift’s 
remark, however, tends to confirm the opinion that it belongs to a 
marine turtle ; and we are not aware, that the ribs of the recent 
Emydes possess such a character. 
The largest ribs in our cabinet must have belonged to a turtle about 
3+ inches in length. 
