HOLOCEPHAU. 115 



3 slender intero-lateral column. Anterior area produced anterior 

 to inner area. ■ External areas on laminar crests of border, pos- 

 terior area very small or less than one-third anterior, and anterior 

 crest produced, or long and narrow, its middle marking anterior 

 end of great inner area. When two mandibular rami are in place 

 it follows from the above that median line of beak forms deep 

 concavity walled in by high anterior outer crest. Posterior outer 

 crest well developed, also prolonged acutely beyond posterior 

 dentinal area. External terminal column largely developed ver- 

 tically. Length about 165 mm. (From Cope.) 



Known only from the above example, the type, said by Cope 

 to approach B. smockii, but of double its size, more compressed 

 and curved, with a much smaller posterior outer dentinal area 

 and a very long anterior outer crest. 



Formation and locality. The type is a large left mandibular, 

 almost perfect, from the marl [Hornerstown K.] at Horners- 

 town in Monmouth County (J. C. Meirs), now in the American 

 Museum at New York. I have not examined this specimen. 



Edaphodon smockii (Cope). 



Ischyodus smockii Cope, Proc. Boston Soc. N. H., XII, 1869, p. 316. New 

 Jersey. Cretaceous Greensand. 

 Cope, Rep. U. S. Geol. Surv. Terr., II, 1875, pp. 284, 288. Horners- 

 town. Greensand No. 5. 



Edaphodon smocki Hussakof, Bull. Amer. Mus. N. H., XXV, 1908, p. 39, 

 PI. 2, figs. 4-5 (type). 



Mandibular moderately long and stout. Outer face uniformly 

 concave transversely, inner also with longitudinal concavity much 

 stronger. Surface striae longitudinal, sometimes broken. Den- 

 tinal areas large, surfaces rather plane, elevated supero-anteri- 

 orly, and plane of posterior face descends abruptly from supero- 

 anterior margin of each. Outer margin, therefore, an incline of 

 two steps, inner of one. Outer areas narrowed in front, and inner 

 areas more obtuse and large, separated by very narrow strip 

 from outer posterior, undivided and extending to inner margin 

 of superior face of mandible. Length about 58 mm. (From 

 Cope.) 



