158 
DR. MANTELL ON THE FOSSIL REMAINS OF TURTLES. 
In the same quarry at Burham, Mr. Bensted has discovered an abdominal plate 
of a small Turtle, and a femur which approximates to that of Trionvx (fig. 6.). 
Fig. 6. 
Femur of a Trionyx ? from the Kentish chalk. Mandible of a Turtle from Lewes. 
The beak of the lower mandible of a Turtle from Lewes (fig. 7 -), is the only other 
Chelonian remain from the chalk formation of England that has come under my ob- 
servation. 
The occurrence of these isolated examples of freshwater (?) Turtles, amidst the ma- 
rine exuviae of the cretaceous epoch, must be referred to the same category as that of 
the Iguanodon in the Kentish rag of Maidstone. They afford evidence of the existence 
of currents that carried far out to sea the carcases of some stray terrestrial and 
fluviatile reptiles, which at length became engulphed in the depths of the ocean with 
the remains of marine fishes and mollusca. In like manner in modern times, Turtles 
which are inhabitants of the Indian and Atlantic oceans, are occasionally drifted to 
the shores of the British Islands ; and doubtless many are imbedded in the deposits 
which are in the progress of formation at the bottom of the European seas. 
Crescent Lodge, Clapham Common , 
May, 1841. 
