Plate II. 



Figure 1. — Skull of the type of P. ingens Marsh, No. 2594, with the anterior cervical 

 vertebrae ; seen from the right side, x 0.28 



Figure 2. — Complete supraoccipital crest of the fragmentary skull of Pteranodon sp., 

 No. 2473 ; seen from the right side, x 0.29 



