Stewart.] Cretaceous Fishes. 307 



the posterior or palatine condyle is comparatively short, and 

 has, in its hinder border, a distinct notch ; in other maxilhe the 

 condyle is longer and, apparently, without the posterior notch. 

 The distance between the condyles appears to be greater in 

 some cases than in others." 



I have been unable to discover any such difference in any of 

 our specimens, but, if this difference does occur, I think that it 

 could not be called a specific character, as there is likely to be 

 almost as much individual variation in Gillicus and Ichtlnjodcctes 

 as in Xiphactinus, in which the variation is remarkably great. 

 The superior border of the bone, back of the condyle, is slightly 

 concave and presents a slight shelf, which probably accommo- 

 dates the jugal. Unfortunately the premaxilla is preserved with 

 none of the specimens, nor has it been found with any of the 

 specimens described by other authors. It was, no doubt, a 

 very small and light bone, thus easily washed away when the 

 soft parts disintegrated. 



Maxilla : Length of alveolar border ( estimated) 97 mm. 



Depth at posterior condyle 24. " 



The dentaries are remarkable for their short length and great 

 depth. The symphysis is very deep, almost vertically directed, 

 and smooth. Just back of it on the internal side there is a 

 broad, shallow and somewhat elliptical-shaped pit, similar to the 

 one found in Saurodon and Saurocephalus. The alveolar border 

 presents a slight convexity near the anterior end, back of which 

 it is slightly concave. The teeth are all very small and form a 

 fringe on the edge of the jaw. The coronoid process is not 

 developed at all, and the lower border is very sharp. Pos- 

 teriorly the bone descends very abruptly to the symphysis. 



Dentary : Depth at symphysis 45 mm. 



Length of alveolar border 55 " 



Length of mandible from cotylus 81 " 



The ceratohyal is preserved in one specimen. It is very thin, 

 much contracted at the center, and expanded at the ends, the 

 posterior of which is concave and the anterior convex. 



The palato-fjuadrate arch is represented by the palatine, 

 mesoptervgoid. pterygoid, and quadrate. The palatine consists 



