478 PEOE. H. G. SEELET ON FUKTHER ETIDENCE 



the posterior extremity, which is broken. It is deepest in front, 

 below the commencement of the teeth, where the vertical measure- 

 ment is about 10 centim. In the middle length, behind the teeth, 

 the depth is about 8 J centim. and at the posterior extremity the 

 depth is 7 centim. The superior or buccal margin, which is sharp 

 externally, is concave in length to behind the teeth ; but the pos- 

 terior half of this contour is convex in length, with the bone 

 flattened above, slightly rounded from side to side, and 3 centim. 

 wide. The inferior contour is convex in front and concave behind, 

 though the thin inferior part of the bone beneath the superior 

 coronoid convexity is broken away. 



The vertical external surface converges forward to the sym- 

 physis, is flattened at the side, with a slight shallow longitudinal 

 concavity in the middle, which increases in depth beneath the 

 coronoid convexity, where it appears to become a narrow lateral 

 perforation through the jaw about 10 centim. from the posterior 

 extremity. The hinder end of the jaw is the condylar articulation. 

 It is terminal, vertical, convex from above downward, wider above 

 than below, and deeper than wide ; it measures 7 centim. deep by 

 4 centim. wide as preserved, but may have been heart-shaped, with 

 a concavity indenting the superior border. Its lateral and inferior 

 margin is rounded. 



Immediately in front of the condyle is a transversely ovate 

 excavation in the external side of the jaw, with its posterior 

 extremity inclined downward. It is fully 7 centim. wide, measured 

 downward and backward, and 3*75 centim. wide measured upward 

 and backward. Its outline is almost that of a perfect egg, with 

 the wide end in front. The floor of this cavity is absolutely flat 

 and vertical, with the elevated margin rising all round it. The 

 articular surface of the condyle forms this margin behind ; the 

 Tipper surface of the jaw makes the superior margin; and at the 

 sup ero- anterior angle the elevation is least. The infero- anterior 

 border is most elevated, rising fully 2-25 centim., extending outward 

 to a sharp crest, in front of which the thickness of the bone 

 diminishes towards the sub-coronoid perforation. This cavity may 

 have given attachment to the masseter muscle, and may be com- 

 pared with the excavation below the condylar region in the Lion 

 and many mammalia. 



The jaw is about 3*75 centim. thick in its anterior half. Not 

 more than .5 centim. of the symphysis between the rami is 

 preserved. It was vertical, and its posterior margin, about 

 10 centim. deep, is convex from above downward. 



The internal surface of the ramus is flattened in front, with a 

 posterior longitudinal concavity in the region of the foramen. 

 The base is rounded, but its median line is a sharp longitudinal 

 ridge. 



The mode of arrangement of the teeth has been described by 

 Sir Eichard Owen ^ as consisting of three parallel rows, extending 

 successively within and behind each other, but the nature of their 

 ^ 0;p. cit. pi. xxxvii. 



