South African Fossil Reptiles and Amphibia. 157 



The snout is narrow and the face short. 



The maxilla passes back to below the middle of the orbit and forms 

 most of the cheek. It has a small palatal portion upon which there is 

 no trace of any molar teeth. 



The septoniaxilla lies wholly within the nostril, forming the 

 posterior lower border, and articulates with the nasal, lachrymal, and 

 maxilla. 



The lachrymal extends from the orbit to the nostril as in Tropido- 

 stoma. It forms a large portion of the anterior border of the orbit, 

 but is much shallower on the cheek. At the nostril it abruptly 

 narrows, and it has a short articulation with the septoniaxilla. 



The nostril is overhung by a small nasal boss. 



The frontal reaches forward to the plane of the back of the nostril, 

 separating the nasals from each other posteriorly. 



The chief features of the skull-top are the slightly thickened supra- 

 orbital border, the width of the intertemporal region, the absence of a 

 preparietal, and the appearance of the interparietal on the top of the 

 skull. 



The postorbital bar is long, but comparatively slender. 



The occipital plate is broad, flat, and vertical. The occipital cou- 

 dyle is small and not tripartite, similar to that of Tropidostoma. 



The foramen jugulare lies on the back of the skull and looks wholly 

 backwards. The paroccipital process is very massive in its outer 

 portion and its outer border inclines strongly medially below. The 

 basisphenoid forms nearly half of the tubera on the inner surface ; but 

 it takes 110 part in the border of the fenestra ovalis, which is bounded 

 posteriorly, medially, and anteriorly by the basioccipital. The fenestra 

 ovalis looks downwards and outwards. The palatal portion of the 

 basisphenoid is short. 



In size and shape the skull agrees most closely with Dicynodon 

 planus, Tropidostoma microtrema, and the form described by Owen as 

 " Oudenodon bainii." From each it is distinguished by one or more 

 characters. 



From Tropidostoma microtrema, with which this form agrees in the 

 primitive state of the lachrymal, the skull differs in the absence of 

 molar teeth, in the fact that the postorbitals and parietals are not 

 developed into lateral crests with a groove between them, and in the 

 absence of a preparietal. 



The skull has many affinities with the type of D. planus, but there 

 is no preparietal. One of the most striking features of the skull is the 

 extension of the lachrymal to the narial border, a feature displayed by 

 Pareiasaurus and other skulls of a primitive type. This condition is 



