2^2 Report S.A.A. Advancement of Science. 



• THEROMOROUS ORDERS. 



PAREISAURIA. 



Small, medium, or large reptiles, with temporal region com- 

 pletely roofed. Distinct postfrontals. postorbitals. squamosals, 

 supra-temporals and quadrato-jugals. Palate Rhynchocei)halian in 

 type ; teeth on pterygoids, palatines, and prevomers. Vertebrae 

 notochordal. Two true sacral vertebrae in Pareiasaurus. Abdcmi- 

 inal ribs unknown— probably absent. Scapula wdth acromion pro- 

 cess ; a well developed cleithrum present. Humerus with entepi- 

 condylar foramen. Pubis and ischium anchylosed forming large 

 median symphysis. Phalangeal formula unknown, but as certain 

 toes have undrvubtedlv 4 phalanges, formula possibly as in Pro- 

 colophon. 



Family : Pareiasauridae. 

 Teeth in regular series on margin of jaws. 



Genera : Pareiasaurus. 

 Elginia. 



Family : Pariotichidae. 

 Teeth in more than one series in one or both jaws. 



Genera : Pariotichus. 

 Pantylus. 

 Hypopnous. 

 Otocoelus. 



Familv : Diadectida?. 

 Anterior teeth conical ; maxillary teeth laterally expanded. 

 Basioccipital looseh articulated. 



(jenera : ? Empedias. 

 Diadectes. 

 Chilonyx. 



THEROCEPHALIA . 



Medium size reptiles, with temporal region .supported 1)y a single 

 lateral arch. Postfrontals u.sually absent (present in Scylacosaunis), 

 postorbitals and squamosals present. .sui)ra-temporals and quadrato- 

 jugals absent. A well developed quadrate. Palate a slight modi- 

 fication of the Rhynchocephalian type. Teeth on pter\goids in 

 Scylacosaurus and ^^lurosaurus. Maxillary and premaxillary teeth 

 flififerentiated as in Mammals into inci.sors. canines, and molars. 

 Occasionally more than one pair of canines; molars simple. Scapula 

 without an acromion process: probal)ly a cleithrum. Manus and pes 

 unknown. 



Family : Scylacosauridae. 

 Distinct postfrontals pre.sent. Teeth on pterygoids, but 

 not on palatines or [)revomers. More than one canine 

 in each maxillarv. 



Genus : Scylacosaurus. 



