NO. 3 



NEW CERATOI'SIAN DINOSAUR GILMORE 



forward at about mid-height along the outer side of the dentary. 

 Above and below this ridge the outer surface retreats obliquely in- 

 ward. 



\'iewed from above, the dental border is straight but is obliquely 

 placed in relation to the lower portion, that is, it passes from the inner 

 posterior margin to the outer anterior margin of the jaw. Beneath 

 the coronoid process there is a deep mandibular fossa which extends 

 forward about one-third the length of the dentary. On the inner 

 side there is the usual row of foramina, leading into the dental cham- 

 ber. The exact number of alveoli cannot be determined at this 

 time, although the tooth series is relatively shorter than in either 

 Ccratops or Triceratops. 



,TrL 



Fig. 3. — Dentary of Brachyccraiops iiw)itancnsis. Type: Cat. No. 7951 

 U. S. Nat. Mus., 1/2 nat. size, c, coronoid process ; m, mental foramen ; sp, 

 surface for predentary. 



At this time little can be said regarding the affinities of Brachy- 

 ceratops, though it would appear most nearly allied to Monoclonius, 

 as shown by its small size, the small brow horns of similar shape, 

 large nasal horn and crenulated margin of the frill without separate 

 marginal ossifications. 



It is readily distinguished, however, from all known Ceratopsians 

 by the longitudinal suture of the nasal horn, the small fenestrse 

 wholly within the median frill element, and the greatly abbreviated 

 facial portion of the skull. It is also apparent that there are other 

 distinguishing features in the skeleton which is to be described 

 later. 



The striking resemblance of the fragment of a skull figured by 

 Hatcher as Monoclon'uis crassns ' to the homologous parts of the 



'Monog. U. S. Geol. Survey, Vol. 49, 1907, p. 74, fig. 76. 



