ii2 CRETACEOUS AND TERTIARY FISH. 



Mandibulars compressed, outer edge rising rapidly from little 

 behind apex, first to a shoulder which supports first exterior den- 

 tinal area, and then steeply to an oblique border which bears hind 

 dentinal area. Dentinal areas very small, inner represented by 

 two columns widely separated from each other. Inner masticatory 

 margin remains parallel with lower edge of jaw, marking one- 

 third total depth. Grinding face vertical behind. External areas 

 very narrow, and behind anterior smaller one appears in position 

 of inner one of B. tripartitus, thus representing outer part of large 

 removed from former, narrow, and extends little anterior to 

 anterior border of anterior outer.. Apex of jaw obtuse, and 

 terminal area on its superior aspect oval, and continues as edge 

 of a lamina along outer margin of beak. No symphyseal plane, 

 whole jaw much compressed and narrowed. Length 70 mm. 

 (From Cope.) 



Said to have much the form of Leptomylns forfex, and ap- 

 proaching B. laterigerus. 



Formation and locality. Only known from the type, a pair of 

 mandibulars now in the collection of the American Museum, 

 N. Y. They are from "Greensand No. 5" [the Hornerstown 

 marl, K.] at Hornerstown in Monmouth County. I have not 

 seen this species. 



Edaphodon tripartitus (Cope). 



Iscliyodus tripartitus Cope, Rep. U. S. Geol. Surv. Terr., II, 1875, pp. 284, 



286. Hurffville, N. J. Upper bed of Greensand. 



Edaphodon tripartitus Hussakof, Bull. Amer. Mus. Nat. Hist., XXV, 1908, 



p. 40, fig. 16, PI. 3, figs, s-6 (types). 

 Iscliyodus mirificus (nee Leidy) Cope, Proc. Boston Soc. Nat. Hist., XII, 



1869, p. 314 (note). 

 Iscliyodus longirostris Cope, Rep. U. S. Geol. Surv. Terr., II, 1875, pp. 284, 



287. Birmingham, N. J. Greensand No. 5. 



Mandibulars little more than twice as long as deep, rami con- 

 verging in slight curve and ending in narrow produced symphy- 

 seal beak. Outer face of mandible with two longitudinal convexi- 

 ties, inner nearly vertical, and with short symphyseal plane. 

 Dentinal areas moderate, anterior border not much produced, 

 inner represented by three adjacent areas or three columns united 

 at their adjacent borders, and outer more than twice as large as 

 either of two interior ones. Latter separated from inner angle of 



