_P. robustus_, Marsh. Am. Jour. of Sc., 3d Ser. vol. iv., p. 218. _P. superbus_, sp. nov. This report, p. 84. _P. leptodus_, Cope. U. S. Geol. Survey, 1872, p. 609. Mysops, Leidy. Pr. Ac. Nat. Sc., 1871, p. 232; U. S. Geol. Survey, 1871, p. 357; Cont. to Ext. Vert. Faun., p. 111. _M. minimus_, Leidy, loc. cit. _M. fraternus_, Leidy. Cont. to Ext. Vert. Faun., p. 112. Pseudotomus, Cope. Pr. Am. Phil. Soc., 1872, p. 467; U. S. Geol. Survey, 1872, p. 610. _P. hians_, Cope, loc. cit. Arctomys, Marsh. Am. Jour. of Sc., 3d Ser. vol. ii., p. 121. _A. vetus_, Marsh, loc. cit. Geomys, Marsh. Am. Jour. of Sc., 3d Ser. vol. ii., p. 121. _G. bisulcatus_, Marsh, loc. cit. Sciuravus, Marsh. Am. Jour. of Sc., 3d Ser. vol. ii., p. 122. _S. nitidus_, Marsh, loc. cit. _S. undans_, Marsh, loc. cit. _S. parvidens_, Marsh, loc. cit., 3d Ser. vol. iv., p. 220. Tillomys, Marsh. Am. Jour. of Sc., 3d Ser. vol. iv., p. 219. _T. senex_, Marsh, loc. cit. _T. parvus_, Marsh, loc. cit. Tachymys, Marsh. Am. Jour. of Sc., 3d Ser. vol. iv., p. 219. _T. lucaris_, Marsh, loc. cit. Colonymys, Marsh. Am. Jour. of Sc., 3d Ser. vol. iv., p. 220. _C. celer_, Marsh, loc. cit. INSECTIVORA. Omomys, Leidy. Pr. Ac. Nat. Sc., 1869, p. 63; Ext. Mam. of N. Am., p. 408; Cont. to Ext. Vert. Faun., p. 120. _O. Carteri_, Leidy, loc. cit. Washakius, Leidy. Cont. to. Ext. Vert. Faun., p. 123. _W. insignis_, Leidy, loc. cit. Passalacodon, Marsh. Am. Jour. of Sc., vol. iv. p. 208. _P. litoralis_, Marsh, loc. cit. Anisacodon,[4] Marsh. Am. Jour. of Sc., 3d Ser. vol. iv., p. 209. [Footnote 4: Professor Marsh has subsequently used this name to designate a genus of the _Brontotheridæ_. Am. Jour. of Sc., vol. ix., p. 246.] _A. elegans_, Marsh, loc. cit. Centetodon, Marsh, Am. Jour. of Sc., 3d Ser. vol. iv., p. 209. _C. pulcher_, Marsh, loc. cit. _C. altidens_, Marsh, loc. cit., p. 214. Hemiacodon, Marsh, Am. Jour. of Sc., 3d Ser. vol. iv., p. 212. _H. gracilis_, Marsh, loc. cit. _H. nanus_, Marsh, loc. cit., p. 113 _H. pucillus_, Marsh, loc. cit. Entomodon, Marsh, Am. Jour. of Sc., 3d Ser. vol. iv., p. 214. _E. comptus_, Marsh, loc. cit. Entomacodon, Marsh, Am. Jour. of Sc., 3d Ser. vol. iv., p. 214. _E. minutus_, Marsh, loc. cit. _E. angustidens_, Marsh, loc. cit., p. 222. Apatemys, Marsh, Am. Journ. of Sc., 3d Ser. vol. iv., p. 221. _A. bellus_, Marsh, loc. cit. _A. bellulus_, Marsh, loc. cit. Talpavus, Marsh, Am. Journ. of Sc., 3d Ser. vol. iv., p. 128. _T. nitidus_, Marsh, loc cit. CHIROPTERA. Nyctitherium, Marsh. Am. Jour. of Sc., 3d Ser. vol. iv., p. 127. _N. velox_, Marsh, loc. cit. _N. priscum_, Marsh, loc. cit., p. 128. Nyctilestes, Marsh. Am. Jour. of Sc., 3d Ser. vol. iv., p. 215. _N. serotinus_, Marsh, loc. cit. MARSUPIALIA. Triacodon, Marsh. Am. Jour. of Sc., 3d Ser. vol. ii., p. 123. _T. fallax_, Marsh, loc. cit.