NEW SOUTH AFRICAN THEROCEPIIALIAN REPTILES. 



343 



18. On some new Thei-oce[)lia]ian Reptiles from the Karroo 

 Beds of South Africa. By R. Broom, M.D., D.Sc., 

 F.R.S., C.M.Z.S. 



[Received April 13, 1920 : Eead April 27, 1920.] 

 (Text-figures 1-9.) 



I^DEX. Page 



Ictidosuchns lonuiceps, sp. nov 343 



Alopecopsis afanis, gen. et sp. iiov 347 



Moschorhinus kitcJiingi, geii. et sp. iiov 351 



Whaifsia plat i/ceps Houghton 354 



Though more species and genera of Therocephaiians Q,re known 

 than of either of the otlier two large suborders of tbe Carnivorous 

 Therapsida — the Gorgonopsia a,nd the Cynodontia, — the structure 

 of the skull and skeleton is much better known in these later 

 suborders. This is largely due to the fact that the Thero- 

 cephaiians are mainly found in the Lower Beaufort zones, where, 

 owing to tlie petrological conditions, very fine complete spe- 

 cimens are rare. The GorgonopsiaKS which are found mostly 

 in the C istecephalus zone, and the Cynodonts which mainly occur 

 in the Upper Triassic zones, are usually represented by well- 

 preserved skulls with a matrix which can be fairly easily removed. 

 Recently I have been fortunate in discovering one or two very 

 interesting specimens of late Therocephaiians formed in the Upper 

 Endothiodoii and Cestecephalus zones, which add considerably to 

 our knowledge of the Therocephalian skull. 



TCTIDOSUCHUS LONGICEPS, Sp. UOV. 



In 1900 1 discovered near Pearston the reniaius of a very 

 interesting type of Therocephalian Mdiich I described under the 

 name Ictidosuchns ^jrimccvus. Until recently no other specimen 

 of either this genus or species has ever been discovered, and as 

 the type skull is very imperfect, a good specimen of this genus has 

 long been one of our principal desiderata. In Deceml)er 1917, 

 I found at Bruintjeshooyte, between Somerset East and Pearston, 

 a good skull, which may be referred to the genus Ictidosuchns, 

 though a distinct species from /. privuevus. 



The skull is nearly complete, lacking only the incisor portion, 

 the occipital condyle, the arches of the left side and the quadrate 

 region of the righit. The palate is much weathered on the left 

 side, but nearly perfect on tlie right. 



As preserved, the skull measures in greatest length 135 mm., 

 and when complete was probably 152 mm. long. Tiie greatest 

 breadth is about 84 mm. From the front of the orbit to the 

 base of the canine is 52 mm., and from the front of the orbit to 



