EXPLANATION OF PLATE 13. 

 Shastasaurus alexandrae n. sp. 



Lower side of the skull of type specimen, represented one-third natural size. 



V, cervical vertebra, probably the third. 



R, cervical rib. The head slightly injured in preparation. 



H, thyrohyal. 



A, angular. 



Sa, supra- angular. 



Sp, splenial. 



X, coronoid. ( ? ) 



Mx, maxillary. 



PI, palatine. 



Pt, pterygoid. 



Q, quadrate. 



J, jugal. 



Po, postorbital. 



B, liasioccipital. 



L, undetermined element. 



