4+ PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 10, 
I pointed out the peculiar value of the skull, which arose from 
the nearly entire condition of the preemaxillary bones, which last 
had, up to that time, been displayed by no Dinosaurian fossil, except, 
perhaps, Compsognathus. I further drew attention to the singular 
fact that the incisor teeth, or those contained in the posterior moiety 
of each preemaxilla, were totally different in shape from the maxil- 
lary teeth; and that the anterior moiety of the premaxilla was 
beak-like and edentulous. Moreover I expressed the opinion that 
while the affinity of the reptile with Jguanodon was clear, the ex- 
tent of that affinity could only be determined by further critical 
comparisons. 
I lost sight of the specimen for a long time; but, some months 
ago, hearing that it was in Mr. Fellows’s keeping in London, I 
requested Mr. Fox’s permission to subject it to more careful study. 
That permission was very readily and liberally accorded by Mr. 
Fox, and I now offer the results of this further work to the Society. 
The skull (PI. I. fig. 1), when entire and undistorted, must have 
had a length of rather less than four inches (probably about 3-8 or 
3°9). The greater portion of the roof and of the right upper maxil- 
lary apparatus, with a part of the occipital surface, are displayed. 
The whole left nasal bone is exposed, together with part of the left 
premaxilla and a portion of the left ramus of the mandible. 
Two relatively large supratemporal fosse, each about three- 
quarters of an inch long and four-tenths of an inch wide, lie at the 
sides of the parietal region, which is somewhat narrow in the middle, 
but expands at each end. ‘The parietal bones (Pa) are a good deal 
injured, but they appear to have inclosed an oval median parietal 
foramen. In front, they unite by a transverse suture with the large 
frontal bones (fr). Each of these is 1-4 inch long, 0-5 inch broad 
behind, and rather narrow ‘in front, flattened though slightly con- 
cave from side to side, and somewhat convex from before backwards. — 
The inner edges of the two frontal bones are a little raised where they 
unite in the frontal suture. The nasal bones (Va) are very large, being 
as long as the frontals, and very nearly as broad behind, where 
they are flattened and continue the direction of the roof of the skull. 
Anteriorly they narrow ; and their outer surfaces, becoming convex, 
look somewhat outwards. Hach nasal bone ends by a deeply concave 
rounded free margin, which bounds the nostril (V) above, and sends 
down a slender process on each side. The inner of these bounds 
the greater part of the inner side of the nostril, and lies upon, and 
internal to, the anterior ascending process of the preemaxillary bone 
(Pmx). The outer, in like manner, applies itself to the anterior edge 
of the ascending process of the maxillary, and forms a part of the 
outer boundary of the nostril. 
The preemaxilla is a very large and remarkable bone. The body, 
or dentigerous portion, is 0°8 inch long and 0-3 inch high, from the 
alveolar edge to that which bounds the nostril below. The greater 
part of the outer surface of the bone is smooth; but towards its 
anterior end it becomes rugged and pitted, and seems to have been 
produced downwards and forwards into a short beak-like process. 
