the spinal marrow , &c. of the Proteosaurus. 163 
the section of the teeth determine their mode of growth to 
be the same as in the crocodile. 
At the close of this paper, I have much satisfaction in 
stating, that the bones of the pelvis, the only ones not yet 
described, have at last been brought under my observation, 
in a specimen found at Wat chet, in Somersetshire, and lately 
purchased for the Museum of the Royal College of Surgeons 
in London. The specimen is four feet six inches in length, 
and in consequence of the bones having been little disturbed, 
is in all respects more complete than any other specimen that 
has been met with. The bones of the pelvis are, however, 
in this specimen too much pressed upon one another to 
admit of a satisfactory drawing being made cf them ; but 
they resemble so closely those of the crocodile, as to make 
any representation unnecessary. 
All the fossil bones of the proteosaurus which I have de- 
scribed, belong to the same species ; but I have seen bones 
of another species, which differs from this in the following 
particulars — the upper jaw is much longer, narrower, and 
comes more to a point ; the teeth were so loosely fixed in the 
jaws, that hardly any are met with in their sockets ; that 
part which had been enclosed by the gum was grooved ; the 
other portion is very slender, has a polished surface, and 
comes to a sharp point. 
The long bone belonging to the anterior fin in both spe- 
cies is as large again as that belonging to the posterior, but 
both these bones are flatter and longer in the new species ; 
and where articulated with the two small bones of the fin, 
send a short process between them ; there is also a deep notch 
on the outer or lower side of one of these two small bones. 
