NO. 2260. 2VEW RESTORATION OF TRWERATOPS—GILMORE. 



103 



homologies of these bones and also furnish corroborative evidence in 

 support of the conclusions reached by me in an enrlier study of a 

 juvenile skull of Brachyceratops ^ montanensis. 



In plate 8 is shown a fragmentary skull (Cat. No. 5740, U.S.N.M.) 

 in longitudinal section. It is known by the field designation as Sk. 27, 



Fig. 1. LOXGITUDINAL SECTION OF SKDLD SHOWING BRAIN CAVITY OF TuiCERATOrS, FROM 



No. 5740, U.S.N.M., about one-eighth natural size. B. oc. pr., basioccipital proc- 

 ess ; CAR., foramen for left carotid artery ; D. so., anterior end of dermosupraoc- 

 ciriTAL ; F., POSTERIOR portion of frontal ; Mx., maxillary ; Oc, occipital con- 

 dyle ; p., PARIETAL, it ALSO EXTENDS FORWARD AROUND THE PINEAL FORAMEN TO MEET 

 THE THICKENED POSTERIOR END OF THE FRONTAL; PIN., PINEAL FORAMEN; PIT. F., PITUI- 

 TARY fossa; pt. f., postfrontal; pt. ff., postfrontal fontanelle ; s. oc, suprv- 



OCCIPITAL ; v., FORAMINA FOR EXIT OF SUPPOSED VEINS; I, II, III, IV, V, VI, VII, VIII, 

 IX, X, XII, FORAMINA FOR EXIT OF CEPHALIC NERVES OF CORRESPONDING NUMBERS. 



and was collected by Messrs. J. B. Hatcher and A. D. Sullins, in 1891 

 on Doegie Creek,^ Niobrara Countj' (formerly Converse County), 



1 1'rofessional Paper lO.*?, U. S. Geol. Survey, 1915. 



»In plate 4n of Monosiaph 40. TJ. S. Orolosical Survey, 1907, Sk. 27, Is indicated on 

 the map as having been found on Bull Creek, but in figure 53 (p. 207) of the Dinosaurs 

 of North America this? same stream is designated Doegie Creek, which agrees with the 

 original lalxi found with the specimen. The former is probably an error made in trans- 

 scribing the legends on the map. 



