POPOSAURUS GRACILIS, A NEW REPTILE 



519 



At this point, the greatest width of the diapophyses, the two 

 tubercular facets are approximately 50 mm. apart. Near the mid- 

 length the diapophysis is supported below by two thin diverging 

 buttresses, the anterior one confluent below with the upper anterior 



Fig. 2. — Poposaurus gracilis. 2a, right lateral view of one of the dorsal vertebrae. 

 2b, posterior view of the same. 2c, left lateral view of second caudal vertebra. All 

 about I natural size. 



face of the centrum. Just before reaching this point it is con- 

 siderably swollen to form the capitular facet for the reception of 

 the rib. The posterior support is directed toward the upper pos- 

 terior face of the centrum, but loses its identity before reaching that 



