16 
end of the snout it measures ‘66 inch, and at the eleventh pair of 
teeth, ‘78 inch wide. Opposite the seventh pair of teeth the skull 
curves upward suddenly and considerably, which is not the case at 
any part of the corresponding portion of the skull of P. longirostris ; 
it is therefore probable, that although in the number and disposition 
of the teeth in the upper jaw, as far as our evidence goes, it strongly 
resembles longirostris in its structure, yet in the length of its skull it 
is probably shorter in proportion than that species, apparently in that 
respect being intermediate between longirostris and crassirostris; thus 
uniting the long-nosed with the short-nosed species of Pterodactyls. 
There are no remains of the cavitas narium in the new species, but 
it is not to be expected that it should make its appearance so near to 
the termination of the snout, as in Jongirostris the distal portion of 
that cavity is situated as far backward from the last of the dental 
series of the upper jaw as that tooth is from the end of the snout. 
The number of teeth on each side of the upper jaw in P. longirostris 
is twelve, and the like number of sockets are apparent in our speci- 
men; it is therefore probable that we have the whole of that portion 
of the head. 
If we estimate the size of the head on the scale of P. longirostris, 
it would appear to be 25°52 inches in length ; but as we have observed 
that the skull curves upward considerably at the seventh pair of teeth, 
it is probable that its length may not be so much. 
The length of the wing of P. crassirostris in proportion to the 
length of its head is 3-91 times. The length of the wing of P. longi- 
rostris compared with the length of its head is 2°51; if therefore 
we assume, from the peculiar form of the snout of P. Cuvieri, that 
the head as regards length is intermediate in its proportions between 
P. crassirostris and P. longirostris, it should be 3°21 parts of the 
length of the wing. 
The snout contracts in width gradually upwards from the sockets 
of the teeth, so that its upper portion forms a narrow ridge, and this 
is its form as far backward as it can be traced. The palatal bones 
are depressed, the suture forming a prominent ridge as far as it is 
visible, but not in so great a degree as in P. giganteus. 
One of the first pair of teeth remains in its socket ; the whole of 
the other large teeth are displaced, but there are two of them imbed- 
ded in the chalk, one within an inch and the other an inch and a half 
of the sockets, and in the fifth right and eighth left socket there is a 
rudimentary tooth in situ. The largest of the displaced teeth ex- 
ceeds 1°32 inch in length, and has been buried in the socket for nearly 
an inch ; the second large tooth, which is imbedded near the third 
pair of sockets, does not exceed an inch in length; both teeth are 
slightly curved, smooth, and are hollow at the base. 
The great diversity in the size of these remarkable Reptiles will ren- 
der a short review of some of the known species interesting ; and if we 
arrange them in order, as they increase in size, the following will be 
the series :—1. P. brevirostris, 2. P. longirostris, 3. P. crassirostris, 
4. P. Bucklandi, 5. P. grandis, 6. P. giganteus, 7. P. Cuvieri; and 
to these may be added the bones in the possession of Mrs. Smith, the 
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