152 CRETACEOUS AND TERTIARY FISH. 



more or less pleurodont, but extremity of root received into 

 conic fundus of alveolus. Premaxillary bones well developed, 

 maxillaries more so, and enter largely into composition of mouth 

 border. Well developed angle of mandible. 



This family differs from the Chirocentridce in its dentition. 

 All its species are extinct. Genera about 21. I may note that 

 P achy r his odus Dixon 1 is antedated by Raphiosaufus Owen, 2 and 

 therefore the present family appellation should stand as above 

 rather than as Pachyrhizodontidce. 



Genus CONOSAURUS Gibbes. 



Conosaurus Gibbes, Smiths. Contrib. Knowl., II, 1851, p. 9. Type Conosaurus 

 bowmani Gibbes. 



Conosurus, auct. 



Conosaurops Leidy, Proc. Acad. Nat. Sci. Phila., 1868, p. 202. Type Cono- 

 saurus bowmani Gibbes, virtually, as this name proposed to replace 

 Conosaurus believed preoccupied. 



Detached teeth conic, in transverse section circular, solid, 

 sharp-pointed, slightly curved backward, fluted near base on 

 inner face with smooth and fine enamel, and with an expanded 

 osseus support. 



Only a single species. 



Conosaurus bowmani Gibbes. 



Conosaurus bowmani Leidy, Proc. Acad. Nat. Sci. Phila., 1868, p. 200. 



(Greensand of Burlington Co.) 

 Conosaurus bowmanii Cope, Rep. U. S. Geel. Surv. Terr., II, 1875, p. 276. 



(Greensand of Burlington Co.) 



Fragment of jaw slightly compressed, outer surface above less 

 inclined than inner above, also former nearly plane or scarcely 

 convex and latter slightly concave with inclination extending 

 well down. As viewed above fragment slightly convex in general 

 contour. At present three teeth alternate with four deep alveoli, 

 latter appear as slightly ellipsoid pits of rather large size when 



1 Geol. Sussex, 1850, p. 374. 



- Rep. Brit. Assoc. Adv. Sci., 1841 (1842), pp. 145, 190. 



