HOLOCEPHALI. 139 



Leptomylus forfex Cope. 



Leptomylus forfex Cope, Proc. Acad. Nat. Sci. Phila., 1875 (Feb. gth), p. 19 

 (nomen nurum). New Jersey Cretaceous. 

 Cope, Rep. U. S. Geol. Surv. Terr., IT, 1875, p. 281. Hornerstown and 



Barmsborough, N J. Greensand No. 5. 

 Hussakof, Bull. Amer. Mus. Nat. Hist., XXV, 1908, p. 41, PL 3, figs. 1-2 

 (type). 



Mandibular much elevated, elevation being- confined to outer 

 side which rises as a lamina, causing masticatory face nearly 

 vertical much its length, and but short extent level to apex. 

 Slight marginal swelling where anterior outer dental should be, 

 and an abrupt rise in margin to position occupied in Bdaphodon 

 by posterior outer area. Inner border of masticating surface 

 parallel to inferior border of jaw except where two> converge to 

 apex, here entire face included between them, occupied by large 

 symphyseal facet. Inner dentinal area represented by narrow 

 acuminate patch on inner angle of masticatory face opposite 

 tuberosity representing anterior outer. Apical area very narrow, 

 extends same distance along exterior angle of superior face. 

 Length 135 mm. (From Cope.) 



Cope also notes that the palatal found in connection with the 

 mandibles of Bdaphodon mirificus does not pertain to them, and 

 is only inferentially referred to this species. The resemblance 

 to the species is very great. Its oblique superior and outer face 

 greatly extended, while inner narrow and vertical. Usual 

 superior groove present, close to edge of latter. Inferior border 

 quite thin. Only two dentinal areas, these exceedingly small and 

 representing outer and anterior inner of species of Bdaphodon. 

 Length 140 mm. 



Formation and locality. Known from the type, described 

 above, from "Greensand No. 5" [the Hornerstown marl, K.] at 

 Hornerstown in Monmouth County (J. C. Miers), now in the 

 American Museum at New York. Cope also had a mandibular 

 and palatal from near Barnsboro in Gloucester County (J. C. 

 Vorhees [probably from the combined Navesink-Hornerstown 

 marl beds, K.]. . 



