36 



THE CERATOPSIA 



Fig. 5. — Palatal view of the skull of Monoclonius (Centrosaurus) flexus, 1/8 natural size, af, anterior process of crest; 

 bo, basioccipital; bs, basisphenoid; e, epoccipitals; exo, exoccipital; mx, maxillary; nar, narial vacuity; oc, occipital con- 

 dyle; f, parietal; ff, parietal fenestra; J>1, palatine; fmx, premaxillary; ff, posterior process of crest; ft, pterygoid; 

 q, quadrate; qj, quadratojugal; r, rostral; so, supraoccipital; sq, squamosal ; /, teeth; vo, vomer. 



the maxillaries into two large vacuities as in Triceratops."'' The region of the palatines and ptery- 

 goids is defective, as they seem to be entirely lacking in our skull, but in the type specimen they 

 resemble those of Triceratops. 



The basi- and exoccipitals, together with the condyle, are fairly well preserved, but are defi- 

 cient in the clarity of their outlines. This is especially true of the limitations of the supraoccipital. 

 From the ventral aspect of the skull of the Yale specimen, the exoccipitals appear as wing-like 



7 Brown, B., 1914, B, p. 557. 



