60 Prof. Owen on the Reptilian Fossils of South Africa. 



The endeavour to fulfil this request has yielded rae the highest pleasure ; and 

 here I must state, that it is chiefly by the timely and active assistance of an in- 

 telligent workman, skilled in removing from fossil bones their hard adherent 

 matrix, and of Mr. Scharf 's well-known artistic ability in preparing the accom- 

 panying illustrations of the fossils, so displayed, — aids, which the President, 

 H. Warburton, Esq., M.P., most promptly and liberally, at his own expense, placed 

 at my disposal, — that I have been enabled so soon to obtain the results which 

 are embodied in the present part of my Report. 



The most remarkable character of the fossils selected for description is that 

 which their discoverer, Mr. Bain, has indicated by calling them ' Bidentals ' : viz. 

 the presence of two long, curved and sharp-pointed tusks, which, like those of the 

 Walrus, Musk-deer and Machairodus, descend, one from each superior maxillary 

 bone, and pass on the outside of the fore-part of the lower jaw. 



This dental character has hitherto been manifested only by Mammals, and is 

 rare in that class : the species above-cited are almost the only ones which present 

 it as conspicuously as do the African fossils under consideration. The first cursory 

 examination however of these crania, as they originally came into my hands, 

 roughly hewn out of their rocky matrix, which concealed most of their anatomical 

 characters, sufficed to demonstrate that they had belonged to a cold-blooded class 

 of vertebrate animals. In one*, the fore-part of the skull showed the median 

 undivided process of a single ' os intermaxillare ' ascending and separating two 

 distinct anterior nasal apertures ; in a second f, the boundaries of a much-con- 

 tracted cranial box were traceable ; both characters combined to prove that the 

 animals to which these fossil skulls belonged had been air-breathing, oviparous 

 and cold-blooded, — in short, Reptilia ; but members, in this class, neither of the 

 Crocodilian nor Chelonian orders. 



No mammiferous animal has the intermaxillary bone single, or the external 

 bony opening of the nasal cavity double : neither Mammal nor Bird has the cavity 

 for the brain so small in proportion to the skull as in the fossil referred to. All 

 Crocodilians, fossil as well as recent, have the intermaxillary bones divided by a 

 median suture, and the anterior nasal aperture single and in the median line, as in 

 Mammals : in all Chelonians the same aperture is single, and perforated in the middle 

 of the fore-part of the skull, just where the specimen with this part most entire 

 and most resembling in its general outward form that of a Tortoise {Dicynodon 

 testudiceps) , presents the convex, imperforate, ascending median plate of the broad 

 intermaxillary bone. Fishes were out of the question, they having no well-defined 

 external respiratory inlets to nasal passages. 



* Dicynodon testudiceps, PI. V, f Dicynodon lacerticeps, PI. III. 



