go COMPARATIVE MORPHOLOGY OF VERTEBRATES. 
Fic. 91.—Skull of Plesiosaurus macrocephalus, after Andrews. ang, angulare; art, 
articulare; ch, choana; jr, frontal; orb, orbit; pa, parietal; pal, palatine; pas, parasphenoid; 
po+pof, postorbital and postfrontal; sf, supratemporal fossa; ¢, transversum. Other 
letters as in fig. 68. 
ws 
siamo tee ere 
S) Wy 
Fic. 92.—Dorsal and ventral views of’ the skull of turtle, “Piles $s, exoccipital; 
m, maxillary; p, (behind naris), preorbital; pno, postorbital; s, supraoccipital; vise 
letters as in fig. 68. 
