12 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [ Nov. 10, 
third digits are quite distinct; but the distal end is entire only in 
the first, or that of the hallux, which measures 1°85 inch in length. 
It has a pulley-shaped articular surface, and is 0°5 inch wide. The 
shaft of the bone is greatly compressed from side to side, as in 
Scelidosaurus. The second and third metatarsals are much broader 
and stouter, with flattened superior faces. They also seem to have 
been longer than the first. The fourth metatarsal looks, at first, as 
if it were much wider than the other; but, on close examination, 
I think I can trace a line of matrix separating a true fourth meta- 
tarsal, of about the same size as the others, from a slender fifth 
metatarsal. A basal phalanx, which seems to have belonged to the 
middle digit, is 1 inch long, 0-6 inch wide at the proximal, and 
0-35 inch at the distal end. The pes of Hypsilophodon, thus, was 
either tetradactyle or pentadactyle. 
The length of the trunk and tail of Hypsilophodon was probably 
about 44 feet; and, in all likelihood, it was mainly herbivorous. 
[For description of Plates I. & IT. see p. 50.] 
4, Furrner Evinence of the Arriniry between the DINosavRIAN 
Reprites and Birps. By T. H. Huxtry, LL.D., F.R.S., Presi- 
dent of the Society. 
On my way to Birmingham, in October 1867, I chanced to meet 
with Prof. Phillips; and mentioning some paleontological inquiries, 
chiefly relating to the Ichthyosauria (with which I then happened to 
be occupied), he very kindly urged me, as I returned to London, to 
pay a visit to the collection under his charge in the University Mu- 
seum at Oxford. I didso; but as we were traversing the museum 
towards the Ichthyosaurian cases, we stopped at that containing the 
Megalosaurian remains, and I may say with Francesca— 
“ Quel giorno pit non vi leggemmo avanti.” 
It is indeed a wonderful collection, ample enough to occupy the 
working hours of many a day; and it was particularly attractive to 
me, as some difficulties in the organization of Megalosaurus and its 
allies had long perplexed me. 
As Prof. Phillips directed my attention to one after the other of 
the precious relics, my eye was suddenly caught by what I had never 
before seen, namely the complete pectoral arch of the great reptile, 
consisting of a scapula and a coracoid ankylosed together. Here was 
a tangle at once unravelled. The coracoid was totally different from 
the bone described by Cuvier, and by all subsequent anatomists, under 
that name. What then was the latter bone? Clearly, if it did not 
belong to the shoulder-girdle it must form a part of the pelvis ; and, 
in the pelvis, the uium at once suggested itself as the only possible 
homologue. Comparison with skeletons of reptiles and of birds, close 
at hand, showed it to be not only an ilium, but an ilium which, 
though peculiar in its form and proportions, was eminently ornithic 
in its chief peculiarities. 
