226 Prof. H. G. Seeley. Researches on the Structure [Mar. 1, 



no incisor teeth, have the hard palate imperfectly developed, and no 

 coronoid process to the lower jaw. 



Another South African group is regarded as indicated by Delphino- 

 gnalhtts, Tapinocephalus, and a new genus named Dinocephalue, which 

 has the largest tusks known in any South African genus, associated 

 with small molars. In the typical genera the skull bones are very 

 thick and the temporal vacuities small. JZlurosanrus is probably to 

 be placed in this group. It is referred to as Dinocephalia. 



Thus there is a series of groups of South African Rep til in which 

 appear to agree in having a palate which has some resemblances to 

 Mammals but approximates to Sphenodoii, Lizards, and Crocodiles. 

 All these sub-orders are combined as the Tberosuchia. In this order 

 or group may be included the Deuterosanria from the Permian rocks 

 of Russia. 



The Deuterosauria is distinguished from the Theriodontia by having 

 palato-nares which open by oval vacuities on a concave surface in- 

 stead of behind a hard palate. The transverse palatine arch is not de- 

 veloped downward. The sphenoidal region is at an angle with the 

 palate, and in the same plane with the occiput. 



Finally, the names given by Professor Cope to allied American 

 types are examined. It appears that the Theromora as hitherto used 

 is a synonym of the Anomodontia, though it might be conveniently 

 limited to the American types, which appear to be distinct from 

 those of Africa and Europe. But it is not possible to use either that 

 name or the names Pelycosauria or Cotylosauria till the characters of 

 the groups they indicate are adequately defined by good characters. 



The relation of the Therosuchia to other Anomodontia is shown in 

 the following grouping. 



ANOMODONTIA. 



THEROSUCHIA. 



Pareiasauria. 



Procolophonia. 

 Gorgonopsia. 

 Dinocephalia. 

 Deuterosauria. 



rLycosauria. 

 Theriodontia. < Cynodontia. 



I Gomphodontia. 

 Endothiodontia. 

 [Theromonu] 

 THKROCHELONIA. 

 Dicynodontia. 

 Kistecephalia. 

 MESOSAURIA. 



