Palæosyops, Leidy. Pr. Ac. Nat. Sc., 1870, p. 113; 1871, pp. 114, 118, 197, 229; 1872, pp. 168, 241; U. S. Geol. Survey, 1870, p. 355; 1871, p. 358; Com. to Ext. Vert. Faun., p. 27; Cope, U. S. Geol. Survey of Terrs., 1872, p. 591.

P. paludosus, Leidy, loc. cit. Cont. to Ext. Vert. Faun., p. 28.

P. major, Leidy. U. S. Geol. Survey of Montana, 1871, p. 359; Pr. Ac. Nat. Sc., 1872, pp. 168, 241; Cont. to Ext. Vert. Faun., p. 45.

P. humilis, Leidy. Pr. Ac. Nat. Sc., 1872, p. 168, 277; Cont. to Ext. Vert. Faun., p. 58.

P. junius, Leidy. Pr. Ac. Nat. Sc., 1872, p. 277; Cont. to Ext. Vert. Faun., p. 57.

P. lævidens, Cope. Pr. Am. Phil. Soc., 1873; U. S. Survey, 1872, p. 591.

P. vallidens, Cope. Pr. Am. Phil. Soc., 1872, p. 487; loc. cit., p. 592.

P. minor, Marsh. Am. Jour. of Sc., vol. ii., p. 36.

Limnohyus, Leidy. Pr. Ac. Nat. Sc., 1872, p. 242; Cont. to Ext. Vert. Faun., p. 58; Marsh, Am. Jour. of Sc., 1872, 3d Ser. vol. iv., p. 124.

L. laticeps, Marsh. Palæosyops laticeps. Am. Journ. Sc. 3d Ser. vol. iv., p. 122.