HATCHER: OSTEOLOGY OF HAPLOCANTHOSAURUS 53 
Mesozoic Formations, pp. 25-43, Plate X., text figures 1-10. The resemblances in 
these two forms are very numerous and are to be seen in the scapulee, as compare 
Figs. 18 and 21; the femur, the ilium and the vertebre as figured and described 
by Owen in his Monograph. Indeed, if the vertebra described as an anterior dorsal 
in the last paragraph on page 29 of his monograph is really an anterior dorsal 
this resemblance would seem to be more than superficial, for according to Owen’s 
description the neural spine seems to be quite simple and the diapophyses are de- 
scribed as being directed upward and outward at an angle of 45° with the neural 
spine, characters precisely like those already described as obtaining in Haplocantho- 
saurus. Unfortunately Owen does not figure this vertebra, and were it not for the 
fact that he describes it as being massive, one 
might readily believe on the evidence of this ver- 
tebra alone that it pertained to a genus closely 
related to or identical with those remains which 
I have made the type of Haplocanthosawrus. 
However the vertebrae of Haplocanthosawrus can 
by no means be considered massive when com- 
pared with the vertebrae of other members of the 
Sauropoda. Moreover, in Haplocanthosaurus the 
vertebrae show numerous large intra-mural cavi- 
ties instead of the close, though cancellous tex- 
ture of these bones, resembling that which obtains 
in the whales, which is present in the British 
genus and which suggested the generic name Fig. 22, Coracoid of Cetiosaurus longus 
Cetiosaurus. This difference in character would Owen, after Owen. {5 natural size. sc, 
seem a very important one, if it were shown to SUT#ce for seapula; 4h, surface for 
exist in those vertebrae of Cetiosaurus which are ™“™™"* 
most cavernous in Haplocanthosaurus. ‘There are, however, other and quite striking 
differences, notwithstanding the general similarity in the o:teology of these two genera. 
The coracoid, according to Owen, is especially different, as will be apparent after a 
comparison of Figs. 19 and 22. If Owen’s figure is correct the coracoid of Cetio- 
saurus is without a foramen, a character which, if correct, is entirely unique, in so 
far as am aware, among not only the Sauropoda but ithe herbivorous dinosaurs 
generally. It appears to me quite possible that Owen’s figure is erroneous and that 
the coracoid is so distorted or imperfect as not to show a foramen in the example 
from which his drawing was made. It does not seem possible that such a striking 
difference could normally have existed in the coracoids of two genera otherwise so 
