42 CALIFORNIA ACADEMY OF SCIEN(JES 



EXPLANATION OF PLATE LIL 



Thalattosmtrus shastensia. 

 All pijnrrx three fourths imtural size. 



Fig. L Superior view of craniiini. 



Fig. 2. Lateral view of craniiim and luaiulihle. 



Fig. 3. Lateral view of skull from right side. 



Legend. 



osai 

 te 



M, maxillary ^'j, squanio 



Pin, preniaxillary Q, quadrate 



N, nasal Ep, epipterygoid (?) 



F, frontal /'', i)alatine 



Pr, parietal 1', prevomer 



Pn, pineal foramen Ar, articular (?) 



Pf, prefrontal -4«, angular 



Pto, post-fronto-orl)ita1 '"^n, supra-angular 



Ptg, groove for post-fronto-orliital D, dentary 



,/, jugal !^p, splenial 



Sc, sclerotie j>lates 



