Fossi/ Nrjjfi/rs. 385 



It is quite impossible from the i-emains to say wliethei- the 

 animal was a T/ii'/'ocr/zJia/idn or not. The structuie ot" the canine 

 closely resembles that of the Dinotrjiltaliitii^ such as Tifanosifchus, 

 but the molar teeth are very diffei-ent. There is no resemblance 

 to the PeJi/rosa/Hrs of America. Provisionally it may be safest to 

 place A/'cJi/rosHchus'dmong the TheroceplKdiaus till further remains 

 are found. At present the earliest ThcroccplKiJ iam^ occur in beds 

 which are a])parently upper Permian, whereas the horizon of 

 A/r/if/'osuc/iNs is prol)ably very much lower, and in beds which are 

 prol)al)ly either midtlle or lower Permian. 



PclosHchus jji'iscus, n. p;. et n. sp. 



This new genus and species is founded on the remains of a 

 lai'ge fossil reptile discovered by Mr. P. H. du Plessis on the farm 

 Bokfontein, Prince Albert district. Most of the remains have been 

 badly weathered and broken, and some which it was inconvenient 

 to remove are still in the rock. The only portions of the skull 

 that have been found are the front of the right dentary, and a 

 })ortion of the palate, but of the skeleton there have been secured a 

 number of well preserved vertebrae, portions of the shoulder girdle 

 and pelvis, some ribs, a moderately complete femur and many 

 fragments of other long bones not yet identified. 



The dentary is very badly weathered and the teeth are lost 

 with the exception of three roots. The portion preserved measures 

 about 140 mm. It shows the symphysis in a fair state of pre- 

 servation, and judging by the position of the symphysis to the 

 ramus we may infer that the two rami made with each other an 

 angle of about 60^. In general appearance the portion of jaw is 

 not unlike that of a crocodile and differs from jaws of Therocepha- 

 lians or Dinocei)halians in that the teeth cannot be distinguished as 

 incisors, canines or molars. There are in the specimen the remains 

 or sockets of 8 teeth. Of these the first five, represented only l)y 

 the sockets, have been large, the first being apparent!}' largest and 

 the others gradually decreasing in size. The length of jaw occupied 

 by the first five teeth has l)een about 100 mm. The socket of the 

 third tooth measures 12 mm. anteroposteriorly and 17 mm. tians- 

 versely, and the distance between the third and fourth tooth has 



