1869. ] HUXLEY—DINOSAURIA AND BIRDS. 31 
from the ilium to the toes, of a half-hatched chicken could be sud- 
denly enlarged, ossified, and fossilized as they are, they would 
furnish us with the last step of the transition between Birds and 
Reptiles ; for there would be nothing in their characters to prevent 
us from referring them to the Dinosauria. 
Discussron. 
Sir Roprrick Murcuison, who had taken the Chair, inquired as 
to the habits of the Hypsilophodon. 
Mr. Hvurxe mentioned that Mr. Fox had two blocks containing 
remains of a large portion of the Hypsilophodon, all procured from a 
thin band of sandstone near Cowleaze Chine. On one the pelvis is 
almost entire, as well as the right femur, the tibia (which is longer 
than the femur), four long metatarsal bones, and.an astragalus. All 
the long bones are hollow. Portions of at least eight individuals 
have been found in the same bed. 
Mr. Szetry doubted whether these animals should be called Rep- 
tiles at all, as they seemed to him to form a group distinct alike 
from reptiles, birds, and mammals, but occupying an intermediate 
position. In the hinder limbs of Péterodactylus the analogies were 
closer with mammals than with birds. He thought it possible that 
the peculiar structure of the hinder limbs of the Dinosauria was due 
to the functions they performed rather than to any actual affinity 
with birds. 
The Prusrpent, in reply, stated that Hypsilophodon, from the 
character of its teeth, probably subsisted on hard vegetable food. 
He expressed a hope that Mr. Fox would allow a closer examina- 
tion of his specimens to be made. He was unable to agree with Mr. 
Seeley’s views. He was inclined to think that the progress of know- 
ledge tended rather to break down the lines of demarcation between 
groups supposed to be distinct than to authorize the creation of fresh 
divisions. 
NovempBer 24, 1869. 
Robert Arnold Barker, M.D., Civil Medical Officer, Cachar, Bengal, 
was elected a Fellow of the Society. 
The following communications were read :— 
