Discussion.
The President (Mr. Evans) remarked that Prof. Owen's paper was a most important and suggestive one, especially as regarded the views advanced respecting the connexion between these old Carnivorous reptiles and the Mammalian Carnivores.
Prof. Seeley remarked upon the extraordinary characters presented by the creature described by the author, and expressed his regret at the want of additional materials, which might have thrown a further light upon the difficult and important questions raised in the paper. He thought that if all the forms referred to the Reptilia were to be regarded as belonging to that class, the latter would be rather difficult to define. The present representatives of the Reptilia are the Chelonia, Crocodilia, Lacertilia, and Ophidia; and any forms departing from these are not strictly Reptiles in the ordinary sense of the term. He thought the present fossil presented some Chelonian characters, but that in many Lizards we may find indications of a dentition similar to that of the fossil. He considered that there could be no doubt as to the connexion between Reptiles and Mammals, and that Prof. Huxley was wrong in his views as to the relationship between Birds and Reptiles. Every mammalian type has a reptilian brain in its earliest stages. The suggestion of the formation of a new order seemed to him to be founded upon certain points which could not be regarded as absolutely proved.
Prof. T. Rupert Jones congratulated the Society on having been the medium of publication of the magnificent series of Fossil Reptiles characteristic of South Africa. He was sure that to Prof. Owen it must be a heartfelt pleasure to have been the immediate elucidator of these wonderful creatures of manifold and rare structures, brought out by his many years of continued labour on the collections made by Bain, Orpen, Atherston, and others. Together with the illustrated descriptions of Professor Huxley, his lucid and powerful expositions have made the history of these creatures known to the world; and they will prove a lasting monument of his persevering and elucidative work. Prof. Jones added a few words on the geological occurrence and distribution of the Dicynodont and associated Reptiles in the Karoo formation of South Africa, its lacustrine or estuarine origin, its enormous thickness, wide extent, and probable age as early Mesozoic.
Prof. Duncan maintained the necessity of accepting the Reptilian type as here understood by the author, and remarked that the embryonic forms of mammals are reptilian. The question seemed to him to be one of probabilities. The old beds contain the foreshadowings of higher forms of animals.
Prof. Owen, in reply, stated that after thirty years of work on fossils he had arrived at the conclusion that the artificial line between the Palæozoic and Mesozoic series seems to need to be raised so as to include the Trias. The onty fossil fish from the beds yielding the fossil described appeared to be Palæozoic. He justified the reference of the fossil to the Reptilia, and remarked that in no Reptile does the ramus of the lower jaw consist of one piece.
