EXPLANATION OF PLATE 12. 



Cymbospondylus petriinut Leidy. 



Posterior limb and arch elements, no. 9947. From the Middle Triassic 

 of West Hmnboldt Range. Nevada. 

 All figures one-third of natural size. 



Fig. 1. Right ? ilium, posterior side. 



Fig. 2. Left ? pubis, superior side. 



Fig. 3. Left 1 ischium, superior side. 



Fig. 4. Right "? ilium, inner side. 



Fig. 5. Left 1 posterior limb. F, femur ; T, tibia ; Fb, fibula ; Trs, tarsals. 



[1801 



