J. W. HULKE ON ORNITHOPSIS. 761 
yet so recent that sufficient time for their complete investigation 
has probably not elapsed; but from the clear, though extremely 
reduced, figures given by Prof. O. C. Marsh, I infer that in Moro- 
sawrus the cervical vertebral centrum is less depressed than in 
Ornithopsis. The same figures also show that its parapophysis had 
a conspicuous pit in its upper surface, as in Camarasaurus, Cope*. 
The side hollow appears also less narrow in the cervical centrum 
of Morosaurus, and the ridges crossing its bottom are differently 
directed from what they are in Ornithopsis. The cervical centra are 
less elongated in Apatosaurus. In Allosavrus the vertebre have 
zygosphene and zygantrum, but the centra have not side chambers. 
Only caudals of Diplodocus have been yet made known; they are 
extremely long—the combined length of four exceeded 34 inches. 
The cheyrons are peculiar. Comparison of Ornithopsis with it is 
not yet possible. 
The comparison of Ornithopsis with the Colorado Dinosaurs 
has brought out in the presacral vertebrae such noticeable concor- 
dances that a family affinity cannot be doubted; but it has also 
shown the existence of such important differences that the generic 
distinctness of Ornithopsis will, I think, hardly be disputed. In 
the main features of agreement, a significant resemblance to Ccteo- 
saurus oxwonensis 1s also discernible. 
Before long, I hope to place before the Society evidence of other 
parts of the skeleton of Ornithopsis from British Wealden beds, 
which will, I believe, greatly assist in establishing its nearest 
affinity. 
Discussron. 
Prof. Srezny stated that in giving the name Ornithopsis Hulkit 
to the two vertebre which he had studied in 1869, which were the 
only parts of this animal then known, he desired to call attention 
to the remarkable avian resemblances of the bones. ‘The large 
deep pits in the vertebrae had reminded him of the similar, but re- 
latively shallower, pits which impress the dorsal vertebrae of Gulls. 
He had regarded the character as “ bird-like,” but had neither 
stated nor believed that it justified an inference that the animal was 
able to fly; for he had regarded the type as intermediate between 
Dinosaurs, Pterodactyles, and Birds; and perhaps that conclusion 
was not so far from the truth as it might have been, considering the 
materials on which it was founded. He accepted generally the 
conclusions at which Mr. Hulke had arrived as to the nomenclature 
and relations of the British forms of Ornithopsis, but thought that 
subgeneric differences were to be detected in Prof. Cope’s American 
types. With regard to the systematic position of the group, he 
still thought there were grounds for placing the animals in a new 
subordinal division, especially in the characters of the pneumatic 
cavities which excavate the centrums; but in face of the circum- 
* Proc. Amer. Phil. Soc. vol. xvii. 
