1869. ] HUXLEY—CLASSIFICATION OF DINOSAURIA. 37 
saurus, in the Kupferschiefer, and two others, Phanerosaurus and 
Sphenosaurus, different from them and from one another, in the 
Rothliegende, in which formation also a peculiar Labyrinthodont, 
Osteophorus, occurs. 
Proterosaurus appears to me to be a true Lacertilian. At least, 
neither in Von Meyer’s figures and descriptions, nor in the one clas- 
sical specimen which exists in this country can I find evidence of 
any essential departure from the old Lacertilian plan of structure, 
such as is exhibited by Hyperodapedon or Telerpeton—though it 
must be confessed that the long neck, light head, and short fore- 
limbs, to say nothing of the opisthotonic death-spasm which has 
left the fossils in their present position, remind one curiously of 
Compsognathus. 
Parasaurus has four ankylosed sacral vertebrae, with great sacral 
ribs; and perhaps the two vertebra which succeed these must be 
counted as sacral. It would appear from the figures, that the ante- 
rior ribs may have been, and probably were, divided into a distinct 
capitulum and a tuberculum. From the position of the undisturbed 
femora in one specimen, it cannot be doubted that the ilia must have 
extended a long way in front of the acetabulum. ‘The length of the 
short and stout femur does not exceed that of four conjoined ver- 
tebrz ; and there is some reason to think that the bones of the leg 
were considerably longer than the femur. 
Parasaurus therefore belongs to a totally different group of rep- 
tiles from Proterosaurus, and I can compare it with nothing but the 
Ornithoscelida and the Dicynodontia. 
The structure of both Proterosaurus and Parasaurus leads to the 
belief that they were terrestrial reptiles ; and their occurrence in the 
Kupferschiefer is no bar to this conclusion, as land-plants abound in 
that rock. 
The Phanerosaurus of the Rothliegende is based upon a series of 
half-a-dozen vertebra, the characters of which are altogether peculiar. 
Sphenosaurus, on the other hand, seems to me to be a Lacerti- 
lian, though of a very different character from Proterosaurus. 
On the whole, I am disposed to think that Parasaurus is related 
on the one hand to the Ornithoscelida and the Dicynodontia, and on 
the other to some much older and less specialized reptilian form. I 
can by no means bring myself to believe that the Reptilia com- 
menced their existence in the Permian epoch with such specialized 
characters as are observable in the four known genera of that age. 
4, The affinities of the OnnitHoscELIpA with Birds. 
I have treated of the relations of the Ornithoscelida with birds 
at length in a former paper, and I will merely repeat here that 
I know of no circumstance by which the structure of birds, as a 
class, differs from that of reptiles, which is not foreshadowed in the 
Ornithoscelida. Nor am I acquainted with any reptiles which can be 
compared in the strength and minuteness of their ornithic affinities 
with the Ornithoscelida. 
It may be said that the form and mode of connexion of the sca- 
