Plate XIII. 



Figure 1. Four free dorsal vertebrae of Pteranodon sp., No. 2616; seen from below. 

 x 1.0 



i 



Figure 2. Fragmentary sacrum of Pteranodon sp., No. 2616; seen from below. x 1.0 

 Figure 3. Sacrum of Pteranodon sp., No. 2489; seen from below, x 1.0 



Figure 4. Five caudal vertebras of the same individual ; seen from above, obliquely. 

 x 1.0 



