30 PROCEEDINGS OF THE GEOLOGICAL society.  [Nov. 10, 
1. There is a great cnemial crest and a ridge for the fibula. 
2. The disposition of the distal end of the tibia is literally that 
observed in the bird. 
Fig. 4, front view. Fig. 5, side view. 
The distal end of the tibia (7), with the astragalus (As), of a young Ostrich 
in the Museum of the Royal College of Surgeons. * the ascending process of 
the astragalus. 
3. There is a fossa for the reception of the ascending process 
of the astragalus. 
4, The distal end of the fibula is much smaller than the proximal, 
though not so slender as in Aves. It cannot articulate with the 
astragalus in the precise way observed in Reptiles. 
5. The astragalus is altogether similar to that of a bird, with a 
short ascending process. I suspect that the perforation observed in 
this process in Lelaps by Prof. Cope, is the opening of a canal or 
canals for tendons, as in the fowl. 
6. The astragalus appears to have remained distinct from the 
tibia throughout life in Megalosaurus; but it seems to have become 
ankylosed in Compsognathus, and Prof. Cope describes it as ankylosed 
in Ornithotarsus. I believe I have evidence of the same coalescence 
in Zuskelosaurus. 
I find that the tibia and the astragalus of a Dorking fowl remain 
readily separable at the time at which these birds are usually brought 
to table. The cnemial epiphysis is also easily detached at this time. 
If the tibia without that epiphysis and the astragalus were found in 
the fossil state, I know not by what test they could be distinguished 
from the bones of a Dinosaurian. And if the whole hind quarters, 
