1869. | HUXLEY—DINOSAURIA AND BIRDS. 1L7/ 
“ The Dinosauria, a group of extinct reptiles, containing the genera 
Iguanodon, Hadrosaurus, Megalosaurus, Poikilopleuron, Scelido- 
saurus, Plateosaurus, &e., which occur throughout the whole series 
of the Mesozoic rocks, and are for the most part of gigantic size, 
appear to me to furnish the required conditions. 
«Tn none of these animals are the skull or the cervical region of 
the vertebral column completely known, while the sternum and the 
manus have not yet been obtained in any of the genera. In none 
has any trace of a clavicle been observed. 
“‘ With regard to the characters which have been positively deter- 
mined, it has been ascertained that :— 
“1. From four to six vertebra enter into the composition of the 
sacrum, and become connected with the ilia in a manner which is 
partly ornithic, partly reptilian. 
«2. The ilia are prolonged forwards, in front of the acetabulum, as 
well as behind it; and the resemblance to the bird’s ilium thus pro- 
duced is greatly increased by the widely arched form of the aceta- 
bular margin of the bone, and the extensive perforation of the 
floor of the actabulum. The other two components of the os inno- 
munatum have not been observed actually in place; indeed, only 
one of them is known at all, but that one is exceedingly remark- 
able from its strongly ornithic character. It is the bone which has 
been called ‘clavicle’ in Megalosaurus and Iguanodon by Cuvier 
and his successors, though the sagacious Buckland had hinted its real 
nature*. But these bones are not in the least like the clavicles of 
any known animal, while they are extremely similar to the ischia of 
such a bird as an ostrich ; and in the only instance in which they have 
been found in tolerably undisturbed relation with other parts of the 
skeleton, namely, in the Maidstone Jguanodon, they lie, one upon each 
side of the body, close to the ilia. I hold it to be certain that these 
bones belong to the pelvis, and not to the shoulder-girdle, and I 
think it probable that they are ischia; but I do not deny that they 
may be pubes. 
* The so-called ‘‘coracoid” of Megalosaurus is the ilium, I am indebted to 
Prof. Phillips, and to the splendid collection of Megalosaurian remains which 
he has formed at Oxford, for most important evidence touching this reptile. 
[I do not know how it came about that I have here confused Dr. Buckland’s 
suggestions with oneanother. In his memoir “ On the Megalosaurus” (Tr. Geol. 
Soc. 2nd ser. vol. ii. p. 396), Dr. Buckland says :— 
“The bone represented in fig. 3 is the outside view of the ilium, slightly con- 
eave. The inner surface is slightly convex, and shows marks of articulation 
with the sacrum.” 
The bone in question is that of which Cuvier makes the remark quoted by 
Prof. Phillips. 
All subsequent writers have followed Cuvior’s determination, which was 
wrong, and ignored Buckland’s, which was not only quite right, but the key to 
a great deal that is most important in Dinosaurian organization. The so-called 
“clavicle” was so named by Buckland himself. Cuvier hesitates to recognize 
it as such, inclining to the belief that it may be the fibula. According to Prof. 
Owen the presence of this clavicle is one of the chief features of the Dizosawria. 
“The chief marks of difference from the Crocodile structure of the scapular arch 
and of resemblance to the Lacertian type is the presence of a distinct pair of 
clavicles.”—Fossil Reptilia of the Wealden Formation, p. 33.] 
VOL. XXVI.—PART I. Cc 
