OSTEOLOGY OF CARNIVOROUS DINOSAURS. 



27 



median anterior surface it is pierced by a small foramen that passes through the 

 bone in a diagonal direction toward the front. The external surface is broadly 

 concave dorso-ventrally and the inner is concave in the same diameter. The ventral 

 anterior border is concave from the mandibular foramen upward and forward 

 meeting the horizontal process that extends forward from the upper anterior surface 

 to lap along the dentary. 



/"■• etr. 



FlG. 15.— POSTERIOR END OF RIGHT RAMUS OF ANTEODEMUS VALENS LEIDY. CAT. No. 4734, U.S.N. M. ALL i NAT. SIZE. A, 



External view; B, internal view; C, supeeior view; ang, angular; a.q, surfaces for articulation with quad- 

 rate; ar, articular; ez.f, external mandibular foramen; /, foramen; pr.ar, prearticular; sur, surangulae. 



Articular (ar.). — The articular is an irregular bone wider than long, and con- 

 stitutes the greater part of the posterior portion of the ramus. The cotylus of the 

 articular has its greatest extent, transverse, deeply bifossate, these fossae being 

 separated by an oblique ridge. The close articulation of the quadrate with these 



