THE SUBCLASS SYNAPSIDA 243 



3. Tribe Therocephalia 



Temporal opening large, bounded below by squamosal and jugal, 

 above by the parietal or the connected postorbital and squamosal.^ 

 No quadratojugals-; quadrates small; a parietal foramen; squa- 

 mosals large; no preparietal. Teeth conical, four or five in pre- 

 maxilla; one or two large upper caniniform teeth, and five to nine 

 smaller ones posteriorly; no secondary palate, or a rudimentary one 

 (? Scaloposauriis) ; prevomers separated or fused (Scaloposaurus) ; an 

 interpterygoidal opening; large posterior palatine vacuities; palate 

 with few or no teeth; postfrontals small or absent; parietal region 

 usually narrow. Mandible with loose symphysis, long dentary, and 

 large coronoid; posterior elements not reduced. Postcranial skeleton 

 largely unknown. 



Family Scylacosauridae. Middle and Upper Permian. Alope- 

 codon Broom, PardosucJms Broom, GlanosiicJms Broom, Scylacosau- 

 rus Broom, Pristerognathus Seeley, Ictidosaiirus Broom, Alopecogna- 

 thus Broom, Scylacorhinus Broom, South Africa. 



Family Ictidosuchidae. Middle and Upper Permian. Idido- 

 suchus Broom, Arnognathus Broom, Cerdodon Broom, South Africa. 



Family Lycosuchidae. Middle and Upper Permian. Lycosuchus 

 Broom, Troclwsuchus Broom, Hyaenasuchus Broom, South Africa. 



• Family Scaloposauridae. Middle and Upper Permian. Scalopo- 

 saurus Owen, Ididognathus Broom, Simorhinella Broom, Icticephalus 

 Broom, Akidnognathus Haughton, South Africa. 



Family Alopecopsidae. Middle and Upper Permian. Alopecop- 

 sis Broom, Scymnopsis Broom, South Africa. 



Family Whaitsidae. Whaitsia Haughton, South Africa. 



Family doubtful. Middle and Upper Permian. Lycosaurus 

 Owen, Eriphosto7na Broom, Lycorhinus Broom, Scymnorhinus Broom, 

 Alopecorhinus Broom, Scylacoides Broom, South Africa. 



1 [In typical Therocephalia, as described by Broom, the postorbital and squamosal 

 do not connect with each other. — Ed.] 

 ^ [See page 239, above. — Ed.] 



