J. W. HULKE ON ORNITHOPSIS. OT. 
fossilized wood so abundant there, and finally had it taken home 
uuder the impression that it was the long bone of a limb. A muti- 
- lated cervical centrum in my collection, which I dug out of the cliff- 
foot near Brixton Chine, is in its present worn state 12 inches long, 
and would have been originally about 2 inches longer (No. 144, 
Coll. H.) 
Its under surface is flattened, and the side is impressed by a long 
narrow pit, the bottom of which is marked with an oblique ridge. 
_I term the lateral hollow in the cervical centra a “pit,” because it 
is a wide-mouthed depression, closed at its bottom, and not in com- 
-Taunication with an internal chamber, the interior of the centrum 
being wholly composed .of large-cancellated issue. The immense 
-spaces of this are well shown in the instructive plate illustrating 
the supplement to Prof. R. Owen’s Monograph on the “ Fossil 
Reptilia of the Wealden,” issued in 1876, in which an exceptionally 
preserved cervical centrum is described under the new name of 
Chondrosteosaurus magnus*. 
Up to this time no other parts of the skeleton than presacral 
vertebree had been identified. Huge limbs or pelvic bones of forms 
commonly referred to Ceteosaurus had been obtained from the same 
bed which had yielded Ornithopsidian vertebree, but not in such close 
association with these as to warrant me in assigning them to this 
genus. JBesides, the widely different character of the bony tissue 
prejudiced both Mr. Fox and myself against such identification, 
probably, as we now have reason to think, wrongly. 
It will be remembered that in 1870 I had suggested that (Hu- 
-camerotus) Ornithopsis and Ceteosaurus owoniensis, with perhaps 
Streptospondylus Cuviert, were members of one genus (this would 
have been more correctly expressed ‘‘ of one family”) in the order 
Dinosauria, characterized by opisthoccelous trunk-vertebre bearing 
a highly complex neural arch, and having a large lateral hollow in 
the anterior part of the centrum, opening externally under the 
neurapophysis ‘. 
In July 1877 a brief notice by Prof. O. C. Marsh of some very 
large reptilian remains then recently acquired by the Museum of 
Yale College appeared to refer to a member of the above family, 
since a ‘‘ very large cavity in each side [of the centrum in the sacral 
vertebre |, connected with the outer surface by an elongated foramen 
below the base of the neural arch,” was mentioned as an important 
character. For the animal indicated by these fossils Prof. Marsh 
made the new genus Titanosaurus, T. montanust. Afterwards, 
finding Titanosaurus preoccupied, he replaced this name by Atlan— 
tosaurus, and 7’. montanus became then A. montanusS. Its femur, 
about 7 feet long, had no prominent third trochanter, but only a 
swelling in its place. 
In the meantime Prof. Cope had, out of other reptilian remains 
* Suppl. Monogr. Foss. Rept. Wealden, pl. v. fig. 2, p. 5 (Pal. Soe. vol. 1876). 
t+ Quart. Journ. Geol. Soc. (1871) vol. xxviii. p. 36. 
t Amer. Journ. Se. and Arts, vol. xiv. pp. 87, 88 (July 1877). 
§ Ibid. p. 514, Noy. 1877. 
