Opinions from J. A. Schiebout 1974
- 'Barylambda jackwilsoni belongs to Barylambda'
- 'Chirox is a subjective synonym of Ptilodus'
- 'Chirox plicatus is a subjective synonym of Ptilodus mediaevus'
- 'Chriacus schlosserianus is a subjective synonym of Tricentes truncatus'
- 'Chriacus truncatus is recombined as Tricentes truncatus'
- 'Claenodon is a subjective synonym of Arctocyon'
- 'Claenodon is a subjective synonym of Arctocyon' according to D. Russell 1964
- 'Ectypodus silberlingi is recombined as Mimetodon silberlingi'
- 'Eohippus is a subjective synonym of Hyracotherium'
- 'Gidleyina is a subjective synonym of Ectocion'
- 'Gidleyina montanensis is recombined as Ectocion montanensis'
- 'Hyopsodus acolytus is recombined as Promioclaenus acolytus'
- 'Ignacius is a subjective synonym of Phenacolemur'
- 'Ignacius frugivorus is recombined as Phenacolemur frugivorus'
- 'Mioclaenus baldwini is a subjective synonym of Protoselene opisthacus'
- 'Mioclaenus ferox is recombined as Arctocyon ferox' according to D. Russell 1964
- 'Mioclaenus ferox is recombined as Arctocyon ferox'
- 'Mioclaenus minimus is a subjective synonym of Promioclaenus acolytus'
- 'Mioclaenus opisthacus is recombined as Protoselene opisthacus'
- 'Neoclaenodon montanensis belongs to Neoclaenodon'
- 'Neoclaenodon montanensis belongs to Neoclaenodon' according to D. Russell 1964
- 'Nothodectes is a subjective synonym of Plesiadapis'
- 'Nothodectes dubius is recombined as Plesiadapis dubius'
- 'Parectypodus sloani belongs to Parectypodus'
- 'Periptychus superstes belongs to Periptychus'
- 'Phenacolemur fremontensis is a subjective synonym of Phenacolemur frugivorus'
- 'Pliolophus is a subjective synonym of Hyracotherium'
- 'Pliolophus is a subjective synonym of Hyracotherium' according to Kitts 1956
- 'Protorohippus is a subjective synonym of Hyracotherium'
- 'Ptilodus douglassi is recombined as Neoplagiaulax douglassi'
- 'Tricentes crassicollidens is a subjective synonym of Tricentes truncatus'