230 ox MAMMAL-LIKE REPTILES. 



South Africa perhaps than the Therocephalia, and pretty certainly 

 earlier than the Anomodonts. 



As so many of our types are founded on imperfect snouts, it 

 will be some time, probably long, before it will be jJossible to 

 divide the Gorgonopsians from the Therocephalians, All we can 

 do at present is to give a list of the known Gorgonopsians and of 

 those that are probably members of that group. 



The known Gorgonopsians are Gorgonops torvus Ovren, Scymno- 

 gnathus tvhaitsi Broom, Scymnogncdhtis iigriceps Broom & 

 Haughton, Scylacojis cajyensis Bi-oom, and Scylacognathus parvtis 

 Broom. 



The following are probably Gorgonopsians: — Tttanosuchus 

 ferox Owen, Titanosuchus cloetei Broom, Scapanodon duplessisi 

 Broom, ArchcBOSuchus cairnci^ossi Broom. 



Besides these there are quite a number of supjoosed Thero- 

 cephalian genera which, on further investigation, may prove to 

 be Gorgonopsians, such as Inostransewia, Eriphostoma, Lyco- 

 smorus, Cynosuchus, Arciognathus, Iciidosaurus, and a number 

 of others. 



Archceosiichus occurs in beds which are Lower Permian. Scyla- 

 cognathus and a number of other probable Gorgonopsians occur 

 in the Middle Permian or Pareiasaurus zone. Gorgonojys and 

 Scy7iinognathus whaitsi are from the Endothiodon zone ; while 

 Scymnognathibs tigriceps and Scylacops capensis are from the 

 Cistecephalus zone or top of the Permian, From the very top of 

 the Cistecejihalus beds a small undescribed Gorgonopsian has just 

 been discovered, so that we can confidently affirm that the Gor- 

 gonopsia extend throughout the Middle and TJpper Permian beds, 

 and that they probably extend from Lower Permian to Lower 

 Trias. 



EXPLANATION OF THE PLATES. 



Ancj. Aiio-ulav. Art. Articular. B.o. Basi occipital. J3.s. Basispheiioid. 

 Co. Coronoid, D. Dentare. JS.o. Exoccipital. Fr. Frontal. I.F. interparietal. 

 Ju. Jugal. L. Lachrymal. M.v. Maxilla. Na. Nasal. JP.A. Prearticular or 

 Gonial. Fa. Parietal. Pal. Palatine. Pmx. Premaxilla. Po.F. Postlroiital. 

 Po.O. Postorbital. P.P. Preparietal. Pr.F. Prefrontal. Pf. Pterygoid. 

 Q. Quadrate. S.Ang. Surangular. Smx. Septomaxilla. Sq. Squamosal. St. Stapes. 

 V. Vomer. 



PlATE XXXVI. 



Scylacops capensis. 



Fig. 1. Side view of skull. Ahoiit \ nat. size. 



2. Top view of skull. A little over f nat. size. 



3. Palatal view of skull. About j nat. size. 



4. Occiput. About i- nat. size, 



Plate XXXVII. 

 Scymnognatlms tigriceps. 



^ig. 5. Side view of skull. Nearlj' ^ nat. size. 



6. Inner aspect of mandible. Nearly ^ nat. size. 



7. Sections across jaw at the places indicated in fig, 6. 



