AND AVES OF NORTH AMERICA. 



31 



Fig. 3. 



Pig. 4. 



NOTHOSAUHTJS ? ANDEIANI. 



External nostrils posterior. 



Pubes entering acetabulum, transverse, united medially. 



Vertebrae with zygapophyses only. 



Ribs single-headed. Chevron bones present. 



SAUROPTERYGIA. 



