1905.] 



PRIMITIVE REPTILE PROCOLOPHON. 



225 



the molar teeth of the mandible, which have not yet been ex- 

 amined. All the teeth contain large pulp-cavities, which extend 

 into the cusps of the crowns. This type of dentition, notwith- 

 standing the suppression of the functional canine teeth, as in 

 MicrogompJwdon, is perhaps more like that of existing lizards than 

 of Theriodonts, though there is a distinct resemblance to the teeth 

 of some South- African Theriodont fossils, and the skull as a whole 

 is not Lacertilian. 



Forms of Skull. — Dr. Schonland in 1895 submitted to me a 

 series of casts of specimens of Procoloi^hon in the Albany Museum, 

 Grahamstown, obtained by Messrs. A. E. and H. TroUip, of Fern- 

 rocks. He subsequently brought the original specimens to the 

 British Museum, and gave me the oppoi'tunity of taking a series 

 of impressions of the more important of them. Figures were 

 prepared and the following notes drafted on these materials. A 

 brief catalogue of the specimens was published by Dr. R. Broom, 

 in 1903, in the 'Records of the Albany Museum,' vol. i. part 1, 

 pp. 8-24, all the specimens being referred to Procolophon trigoni- 

 ceps. Three specimens are figured by him. Among the casts are 

 remains of a species of Petroj^hryne, which need to be carefully 

 separated. 



Text-fi^. 34. 



Impression of a palate of Frocolophon, showing crowns of the molar teeth ; 

 from Fernrocks. 



The Fernrocks specimens appear to be referable to different 

 species from those collected at Donnybrook. Dr. Broom finds 

 but three teeth in each premaxillary, and in some specimens from 

 Donnybrook there are four premaxillary teeth. In the British 

 Museum specimen R. 794 (text-fig. 33, p. 224), which is the only 

 Donnybrook specimen showing the entire palate, the palatal suture 

 between the premaxillary and maxillary bones appears to be trans- 

 verse and in advance of the first pair of maxillary teeth, which 

 are level with the small group of palatal teeth at the anterior 

 extremity of the vomerine bones. In the Fernrocks cast of the 



15* 



