1 84 CRETACEOUS AND TERTIARY FISH. 



The existing forms comprise about 6o> genera, largely in tropi- 

 cal seas. Their dentition is admirably adapted for crushing the 

 shells of mollusks, upon which most of them feed. About n ex- 

 tinct genera have been described, and some few species referred 

 to several of the existing genera. 



Genus PHYLLODUS Agassiz. 



Phyllodus Agassiz, Poiss. Foss., II, pt. 2, 1844, p. 238. Type Phyllodus 

 toliapicus Agassiz, first species, restricted by Woodward, Cat. Foss. Fishes, 

 IV, 1901, p. 546. 



Paraphyllodus Sauvage. Bull. Soc. Geol. France (3) III, 1875, p. 615. Atypic. 



Pharyngeal dentition compact, tritoral, leaf-shaped, showing 

 pile of successional teeth beneath each functional tooth, and mid- 

 dle teeth much larger than marginal teeth. Upper pharyngeal 

 bones apparently fused together with lower pharyngeals. 



This extinct genus is only known from the pharnygeal denti- 

 tion. About 20 or more species have been described. 



Phyllodus curvidens Marsh. 



Phyllodus curvidens Marsh, Proc. Amer. Assoc. Adv. Sci., 1869, p. 229. 

 Miocene Marl, near Shiloh, Cumberland Co. 

 Cope, Proc. Amer. Philos. Soc. Phila., XIV, 1875, p. 362. (Miocene of 

 Cumberland Co.) 



Central portion of pharyngeal dental plate with very thick 

 teeth, longest of which considerably curved, so that crushing sur- 

 face of plate transversely concave. (From Marsh.) 



Marsh says this species is readily distinguished by the un- 

 usual thickness of the teeth and the longest being considerably 

 curved. 



Formation and locality. Known from the Miocene marl near 

 Shiloh [Kirkwood, K.] in Cumberland County. Not seen by me. 



Phyllodus elegans Marsh. 



Phyllodus elegans Marsh, Proc. Amer. Ass. Adv. Sci., 1869, p. 228. Eocene 

 Greensand at Farmingdale, in Monmouth Co. 



Pharyngeal dental plate obtusely triangular, small, and tri- 

 turating surface a little convex. Central teeth enlarged, circular, 



