134 Mr. H. G. Seeley on Prof. Owen's 
regarded by Cuvier and Oken as an infallible sign that go 
Pterodactyle was a saurian reptile, and not a mamma 
this, as in some other parts, the animal shows the greatest 
similarity to the chameleon, in which, however, the back of 
the skull is not arch-like, as in birds, but sharper in its 
backward prolongation, and therefore quite different from 
Pterodact. e It is characteristic of Pterodactylus that the 
articulation of the lower jaw lies more or less in front of the 
posterior angle of the orbit. In birds this region lies further 
backward; and in lizards it is coincident with the posterior 
termination of the temporal fossa. 
* At the same time the lower jaw of the Pterodactyle, except 
in being armed with teeth, closely resembles that of birds. The 
very firm union of its rami, their flat ledge-like form, their 
straight antero-posterior direction, and slight vertical curve, 
the facing of its articular surface (which lies rather backward), 
and the surprising shortness of the process which is behind 
it greatly remind us of the lower jaw in birds, and, among 
reptiles, of the chameleon and the turtle. Sometimes traces 
the spot where both ledges terminate anteriorly, a clear sepa- 
ration between the coronoid and dentary bones may be seen. 
Hence it results that the lower jaw of the Pterodactyles, at 
any rate, 18, even in its composition, only to be comp to 
