242 THE OSTEOLOGY OF THE REPTILES 



1. Tribe Gorgonopsia 



Prefrontals and large postf rentals contiguous over orbit. A dis- 

 tinct preparietal in front of small parietal foramen. Temporal open- 

 ing bounded above by united postorbital and squamosal, below by 

 squamosal and jugal or squamosal only. Parietal region wide. A 

 single vomer (? fused prevomers). No secondary palate; an ecto- 

 pterygoid. No acromion on scapula; no clei thrum; coracoids rela- 

 tively small; a large proatlas. Phalangeal formula primitive 2, 3, 



4, 5, 3- 



A group intermediate, according to Broom, between the Thero- 



cephalia and Anomodontia. 



Middle and Upper Permian. 



Family Gorgonopsidae. Gorgonops Owen, Scymnognathus Broom, 

 Cyniscodon Broom, Cerdognathus Broom, Scymnosaurus Broom, 

 Gorgonognathus Haughton, Scylacognathus Broom, Scylacops Broom, 

 Galesuchus Haughton, Ididomorphus Broom, Aloposaurus Broom, 

 Aelurosaurus Owen, Cynodraco Owen, Tigrisuchus Owen, Arctosu- 

 chus Broom, Arctognathus Broom, Arctops Watson, Theriodesmus 

 Seeley, Asthenognathus Broom, South Africa. Inostrancevia Ama- 

 litsky, Russia. 



Family Ictidorhinidae. Middle and Upper Permian. Ictido- 

 rhinus Broom, South Africa. 



Family Burnetidae. Lower Triassic. Burnetia Broom,^ South 

 Africa. 



2. Tribe Bauriasauria 



A well-formed secondary palate; a median, unpaired vomer; single 

 occipital condyle; the pterygoids extend to quadrates; no post- 

 frontals; squamosal small; quadrate large; parietal foramen present 

 or absent; strong incisors and grinding molars; large posterior pala- 

 tine vacuities. No acromion on scapula. 



Upper Triassic. Bauria Broom, Microgomphodon Seeley, Melino- 

 don Broom, Sesamodon Broom, Aelurosuchus Broom, South Africa. 



1 [Made "the type of a new suborder, Burnetiamorpha, by Broom, 1923. — Ed.1 



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