All the forms described under this head are of uncertain reference.
Elotherium.
_E. lentum_, Marsh. Am. Jour. of Sc., 3d Ser. vol. ii., p. 39.
Platygonus.
_P. Ziegleri_, Marsh, loc cit., p. 40.
Parahyus, Marsh. Am. Jour. of Sc., 3d Ser. vol. xii., 402.
_P. vagus_, Marsh, loc. cit.
Homacodon, Marsh. Am. Jour. of Sc., 3d Ser. vol. iv., p. 126.
_H. vagans_, Marsh, loc. cit.
Ithygrammodon, gen. nov. This report, p. 56.
_I. cameloides_, sp. nov. This report, p. 57.