180 



EEPTILIA 



Sub-Order 1. PAEEIASAURIA. Seeley. {CoUjlosauria, Cope.) 



Head completely covered hy a bony roof; parietal foramen large; narial openings 

 separate. Marginal teeth arranged in a more or less uniform series. Vertebral 

 centra pierced for the persistent notochord. 



The skeletal characters of this group proclaim a very close relationship 

 with the higher Labyrinthodont Amphibians. In the typical genus, Pareia- 

 sawrus, the external bones of the skull are sculptured, but no true mucous 

 canals have been observed. 



Family 1. Pareiasauridae. Coj^e. 



Teeth conical, or with compiressed, cuspidate crown, those on the margin of the jaws 

 arranged in close regular series. Smaller teeth usually present on pcdatines, pterygoids, 

 and vomers. Pelvic hones fused in the adult. Limbs short and stout. Permian 

 and Trias. 



Pareiasawrus, Owen (Fig. 284). Known by tolerably complete skeletons 

 over 2 "5 m. long from South Africa and Northern Russia. Skull broad, 

 depressed, and triangular in form, the external bones coarsely sculptured, but 

 their sutures not clearly distinguishable. Orbits relatively small, laterally 



Fig. 2S4. 



Pareiamnrus haiiii, Seeley. Karoo Formation (Permian or Trias) ; Tambor Foiitein, Cape Colony. 



Skeleton ; 1/20 (after Seeley). 



placed. Occipital condyle slightlv indented. Bones of the palate fused, and 

 bearing several series of small teeth. There are about eighteen presacral 

 vertebrae, each with a deepened articulation for the single-headed ribs. 

 Small intercentra occur between all the dorsal vertebrae ; the four sacrals 

 are not fused. About thirty caudal vertebrae, the anterior ones with short 

 ribs, and nearly all with neural arches and chevron bones. Scapula very 

 long, like that of Dinosaurs. Coracoid small and subrectangular, epicoracoid 

 narrow and triangular ; clavicles robust, meeting in the middle line and resting 

 on the front border of the large T-shaped interclavicle. A supraclavicle also 

 said to be present on each side. Humerus short, massive, expanded at the 



