IN TlIK CAllNIVOROUS DINOCEPHALIAN llErTILES. CTT) 



Class REPTILIA. 



Subclass SYjSAPSIDA Osborn. 



Super-order Tiierapsida Broom. "" 



Order Dinocephalia Seeley. 



Suborder Tapinocepiialia Broom. 

 „ Titanosuciiia Broom. 

 Order D R o M A s A u u i A Broom. 

 Order A N o M o D o N T i A Owen . 

 Order T H E R i o D o N t i A Owen. 



Suborder Therocephalia Broom. 

 ,, GoRGONOPSiA Seeley. 

 „ BuRNETiAMORPiiA Broom. 

 ,, Bauriamorpha Watson, 

 „ CyNODONTiA Owen. 



[Keceivcd May 22, 1923.] 



Addendum (27i/t April, 1923). — A few days after I had sent 

 off the above paper to London, I was very fortunate in receiving 

 from Mr, van der Byl one or two additional specimens, which 

 enable me to give a full description of the Titanosuchian jaw, 

 and thus to complete all the more important details of the skull 

 structure. On a pai-t of the farm, Abraham's Kraal, that had 

 not previously been prospected, Mr, van der Byl discovered the 

 weathered remains of three Titanosuchians, and collected iiU that 

 appeared to be portions of jaws. These, when pieced together, 

 proved to be the practically perfect mandible of a large Titano- 

 suchian, the badly weathered and fragmentary jaws of another 

 of the same species, and the dentaries of a huge Titanosuchian, 

 unlike any other that had previously been discovered. It is not 

 often that a collector makes at one time such an important haul ; 

 atid when we consider that we owe to his discoveries previously 

 made a full knowledge of the skull structure in a group of 

 Maramal-like reptiles hitherto practically unknown, one feels 

 that Mr. van der Byl must be offered the most hearty congratu- 

 lations of the scientific world. 



The lai-ge jaw has preserved the roots of four large incisors, 

 the root of a large canine, and the remains of 15 molars. As 

 most Dinocephalians have lost the crowns of the teeth when 

 discovered, and have been nnmed from the general size and 

 arrangement of the teeth, it is very difficult to be sure whether 

 we are dealing with new forms or Avith species that have 

 previously been named from very imperfect specimens. Owen's 

 Tltanosuchus ferox is admitted to be a most unsatisfactory type, 



