32 



THE EXTINCT BATBACHIA, EEPTILIA 



Pic 



Fisr. o. 



MKCISTOI'S lNTKUMKlHUH. 



Limbs ambulatory, no third trochanter. 



Sacrum of two vertebrae. 



No procoracoid or clavicle. 



Ribs mostly double-headed. 



External nostrils anterior. 



Pubes longitudinal, not entering acetabulum ; free distally. 



Zygapophyses only ; chevron bones 



limbs ambulatory; a third trochanter on femur. 



Sacrum of two or three vertebrae; acetabulum entire; pubes united. 



Ribs double-headed. 



External nostrils posterior. 



Zygapophyses only and chevron bones. 



OKOOODILIA. 



THECODONTIA. 



Limbs ambulatory or prehensile. 



Ilium horizontal, supporting a long sacrum of five or six vertebrae, the anterior derived 



from the lumbar series. 

 The acetabulum thrown forwards, and not complete, but perforate. 



