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 e^ddence goes, it strongly 

 resembles longirostris in its structure, yet in the length of its skull it 

 is probably shorter iu 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 longirostris 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 vring 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 iu 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 iu 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. BucMandi, 5. P.grandis, 6. P. giganteus, 7. P. Cuvieri; and 

 to these may be added the bones in the possession of Mrs. Smith, the 



