70 Geological Society : — 



character of its teeth, probably subsisted on hard vegetable food. 

 He expressed a hope that Mr. Pox would allow a closer examination 

 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. 



November 24th, 1869.— Prof. T. H. Huxley, LL.D., P.R.S., 



President, in the Chair. 



The following communications were read : — 



1. " On the Dinosauria of the Trias, with observations on the 

 Classification of the Dinosauria." By Prof. Huxley, LL.D., F.R.S., 

 President. 



The author commenced by referring to the bibliographical history 

 of the Dinosauria, which were first recognized as a distinct group by 

 Hermann von Meyer in 1830. He then indicated the general cha- 

 racters of the group, which he proposed to divide into three families, 

 viz. : — 



I. The Megalosattrid^, with the genera Teratosaurus, Palceosaurus, 



Megalosaurus, PoiJcilopleuron, Lcelaps, and probably Euskelo- 

 sanrus ; 



II. The Scelidosauridje, with the genera Thecoclontosaurus, Hylce- 



osaurus, Pholacanthus, and Acanthopholis ; and 



III. The Iguai\ t odontid^e, with the genera Cetiosaurus, Iguanodon, 

 Hypsilophodon, Hadrosaurus, and probably Stenopelys. 



Compsognathus was said to have many points of affinity with the 

 Dinosauria, especially in the ornithic character of its hind limbs, 

 but at the same time to differ from them in several important par- 

 ticulars. Hence the author proposed to regard Compsognathus as 

 the representative of a group {Compsognatha) equivalent to the true 

 Dinosauria, and forming, with them, an order to which he gave the 

 name of Ornithoscelida. 



The author then treated of the relations of the Ornithoscelida to 

 other Reptiles. He indicated certain peculiarities in the structure 

 of the vertebrae which serve to characterize four great groups of 

 Reptiles, and showed that his Ornithoscelida belong to a group in 

 which, as in existing Crocodiles, the thoracic vertebrae have distinct 

 capitular and tubercular processes springing from the arch of the 

 vertebra. This group was said to include also the Crocodilia, the 

 Anomodontia, and the Pterosauria, to the second of which the author 

 was inclined to approximate the Ornithoscelida. As a near ally of 

 these reptiles, the author cited the Permian Parasaurus, the struc- 

 ture of which he discussed, and stated that it seemed to be a terres- 

 trial reptile leading back to some older and less specialized reptilian 

 form. 



With regard to the relation of the Ornithoscelida to birds, the 



