1869. ] HUXLEY—CLASSIFICATION OF DINOSAURIA. 30 
2. The anterior prolongation of the ilium is more slender than 
the posterior. 
3. The rami of the mandible unite in an excavated edentulous 
symphysis, which receives an edentulous prolongation of the pre- 
maxille. 
4. The proximal end of the femur is as in the Scelidosauride. 
5. There is no dermal armour. y 
Cetiosaurus*, Iguanodon, Hypsilophodon, Hadrosaurus, and pro- 
bably Stenopelyxt belong to this division. 
These three groups appear to me to be very well marked; but I 
do not propose them with the intention of suggesting that there 
are no others, or that the progress of discovery will leave them 
thus well defined. 
The very remarkable reptile, Compsognathus longipes, has many 
affinities with the Megalosauride, Scelidosauride, and Igquano- 
dontide, but it presents, at the same time, so many differences 
from all these, and so much of its structure is left unrevealed by 
the solitary specimen which exists, that perhaps the most conve- 
nient course which can be adopted, at present, is to make it the re- 
presentative of a group equivalent to them. Compsognathus differs 
from all the preceding forms in the length of the cervical relatively 
to the thoracic vertebre, and in the femur being considerably 
shorter than the tibia ¢. 
2. Establishment of the Order OrnnrrHoscELipA to include the Dino- 
sauria and the Compsognatha. 
But Compsognathus agrees with the Megalosauride, Scelidosau- 
ride, and Iqguanodontide in the ornithic modification of the Saurian 
type, which is especially expressed in the hind limbs; and I there- 
fore propose to unite it with them in one group, which I shall term 
OrnitTHoscELIDA. This group will contain two primary subdivisions ; 
* T assign this place to Cetiosawrus on the evidence of the splendid series of 
remains of this reptile which Prof. Phillips showed me in the Oxford Museum. 
+ Von Meyer has described a reptile from the German Wealden, in the ‘ Pa- 
lxontographica’ for 1859, under the name of Stenopelyx Valdensis. Only the 
pelvis, a few vertebra, and the left hind limb of this very interesting genus are 
preserved ; but they suffice to prove it to bea Dinosaurian. There are four digits 
in the foot, the fifth being absent, while the hallux is smaller than the others. 
The fibula is slender; the tibia stout and apparently as long as the femur, the 
head of which is at right angles with the shaft. The ischia are in place and 
longer than the femur; they are stouter in proportion than in /ywanodon or 
Hypsilophodon, and quite differently formed. What Von Meyer regards as the 
pubes are, if I mistake not, the anterior prolongations of the iia. 
From the absence of any dermal armour, one would be disposed to arrange 
Stenopelyx among the Iguanodontide; but many of its characters are very 
peculiar. 
{ Professor Cope has distinguished Compsognathus as the type of a division, 
Ornithopoda, from the rest of the Dinosauria, which he terms Goniopoda. 'The 
Ornithopoda have the astragalus ankylosed, while in the Goniopoda it is free. 
But there is much reason to believe that the astragalus became ankylosed in 
some of the ‘‘Goniopoda ;” and it seems to me precisely by the structure of the 
foot that Compsognathus is united with, instead of bemg separated from, the 
Ornithoscelida. 3 
D 
