Limnohyus laticeps, Marsh.
Palæosyops Laticeps. Am. Journ. of Sc. v. iv. p. 122.
Specific characters.—"Cranium is broad. The zygomatic arches much expanded. The nasals are narrow and elongated, and more like the corresponding bones in Hyrax than those in the larger pachyderms."
Fragments of the upper molar and premolar series. The species is determined by measurements given by Dr. Leidy of the second upper molar.
LEUROCEPHALUS, Gen. Nov.
Established on a specimen having a nearly complete dentition, and portions of the cranium.
Dental Formula: (I. 3/3, C. 1/1, Pm. 4/4, M. 3/3,) × 2 = 44.
Upper incisors acute, with strong posterior ridges, lower incisors compressed and laniariform, canines compressed, with serrated cutting edges; first upper premolar with rudimentary anterior lobe, last upper molar with rudimentary postero-internal cusp. Molars constructed as in Palæosyops, but higher, with sharper cones and more erect external lobes. Internal median valley very much deeper. Little or no depression at the forehead; zygomatic arch round, comparatively straight and does not project outwards, and with obscure postorbital process. Premaxillaries short and straight. Mandible with nearly straight lower margin, and shallow masseteric fossa; mental foramen single.
Leurocephalus cultridens, Sp. Nov.
This species was considerably larger than Palæosyops major, with which it shows affinities, as also with Titanotherium Proutii. See [Plate IV].