14 



SAUEOPSIDA. 



Characters. — Oviparous (birds) or ovoviviparous (reptiles are eithpr) 

 vertebrata. Single occipital condyle. The lower jaw is compound and does 

 not articulate directly with the base of the skull, but is suspended by the 

 quadrate. Vertebrae have no terminal epiphyses. Eed blood corpuscles 

 oval and nucleated. No corpiis callosum. Embryo has amnion and 

 aUantois.* Gill-slits of embryo close up in the adult, and they never breathe 

 by gills. Sub-divided into : — 



I.— REPTILIA. 



Characters. — Eeptilia have the characters of Sauropsida, plus those 

 given in middle column of above Table. 



SUB-DIAriSIONS. 



See page 16, under Placenta. 



