J. W. HULKE ON ORNITHOPSIS. 
~l] 
Or 
1) 
58. Mote (3rd) on (Kucamerorus, Hulke) Ornirnorsis, H. G. 
Seeley, = BoruRiospoNDYLUS MAGNUS, Owen, = CHONDROSTEO- 
SAURUS MAGNUS, Owen. By J. W. Huuxe, Esyq., F.R.S., F.G.S. 
(Read May 28, 1879.) 
Tue following paper contains a description of an unusually perfect 
dorsal vertebral centrum of Ornithopsis, additional information re- 
specting the cervical and anterior dorsal vertebree, and a comparison 
of its presacral vertebra with those of several recently discovered 
Colorado Dinosaurs, bringing out several concordances but also such 
differences as prove the generic distinctness of Ornithopsis. 
Our knowledge of the skeleton of this remarkable Wealden 
Dinosaur is still so incomplete that I deem myself fortunate in 
being able to submit to the notice of the Society an unusually well- 
preserved vertebral centrum, which I obtained from the sea-cliff, 
near Chilton, Isle of Wight, in 1875; the description of which and 
the remarks that follow may be regarded as a continuation of two 
former notes on the vertebre of this Saurian*. 
This new centrum (No. 178, Coll. Hf) (fig. 1), like that with which 
Fig. 1.—Reduced side view of a Trunk-centrum of (Hucamerotus, 
Hulke) Ornithopsis, Seeley. 
jf. Front. e. Canal. 
Tidentified my neural arch (No. 67, Coll. H) in the summer of 1870 
(the Mantellian fossil, No. 28632, Brit. Mus. Catal., Wealden, S.E. 
England), is characteristically opisthoccelous, the posterior cup being 
deeply hollow, and the anterior convexity correspondingly prominent. 
The contour of the articular ends is oval, the longer diameter verti- 
cal, the upper end of the oval cut off. In its present state the vertical 
diameter of the posterior surface is about 3°5 inches, the horizontal 
diameter about 2-9 inches; but these measures must be regarded 
only as approximative, because the edge of the cup is worn, and 
the whole form is slightly distorted by pressure. I think that when 
the shape was perfect, the difference of the diameters was less 
* Quart. Journ. Geol. Soc. vol. xxvi. p. 318, pl. xxii. 1870; and vol. xxviii. 
p. 36, 1871 (read Novy. 22, 1870). 
t This no. refers to the Catalogue of my collection. I give it because I have 
myself often felt how advantageous it would be to be able, at a future time, to 
identify the actual fossil described by an author. 
