SAURODON. 



10; 



from the Kansas Chalk ; but the presymphysial bone is lacking in front of the 

 truncated dentary. Most of the characteristic teeth are preserved, including those 

 in the hinder part of the dentary on the right side of the fossil. The forward 



Fig. 32. Saurodon intermedins (Newton) ; outline of head with opercular apparatus, the type specimen, 

 two thirds nat. size. — Probably from zone of Schloenbachia variants ; Dover. Gardner Collection 

 (B. M. no. 47250). ag., articulo-angular ; d., dentary; mx., maxilla; op., operculum ; pmx., pre- 

 maxilla ; pop., preoperculum ; qu., quadrate ; sop., part of suboperculum. 



inclination and prominence of the mandible are well shown. The outlines of the 

 much-expanded preoperculum (pop.) and the nearly square operculum (op.) are 

 also distinct. The anterior abdominal vertebral centra, with slight lateral pits, 

 are somewhat longer than deep. 



A maxilla very similar to that of Saurodon intermedins, but ornamented with 

 fine granulations and pittings, has been found in the same formation and locality 

 as the preceding specimen. 



Horizon and Locality. — Probably zone of Schloenbacliia varians .- Dover. 



Family PlethodontidyE. 



Cretaceous fishes more or less closely related to the surviving Osteoglossidas 

 and Albulidse, but not yet sufficiently well known for exact classification. In the 

 skull the parietal bones meet in the middle line, and there is a roofed posterior 

 temporal fossa on each side. A large median dental plate is fixed to the para- 

 sphenoid and opposed to a similar dental plate, which is probably supported by the 

 basihyal bone. 



The only genus known by large portions of the skeleton is Anogmiiis, from the 



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