Opinions from W. D. Matthew 1918
- 'Anaptomorphus minimus is a subjective synonym of Nyctitherium celatum'
- 'Anaptomorphus minimus belongs to Anaptomorphus' according to Loomis 1906
- 'Creotarsus belongs to Creotarsidae'
- 'Creotarsus lepidus belongs to Creotarsus'
- 'Deltatherium absarokae is recombined as Didelphodus absarokae'
- 'Deltatherium absarokae is recombined as Didelphodus absarokae' according to Cope 1882
- 'Diacodon celatus is recombined as Nyctitherium celatum'
- 'Diacodon puercensis belongs to Diacodon'
- 'Entomolestes nitens belongs to Entomolestes'
- 'Ictidops is a subjective synonym of Ictops'
- 'Ictidops belongs to ' according to Winge 1917
- 'Mysops kalicola belongs to Mysops'
- 'Palaeanodon belongs to Metacheiromyidae'
- 'Palaeanodon ignavus belongs to Palaeanodon'
- 'Palaeanodon parvulus belongs to Palaeanodon'
- 'Palaeictidops is a subjective synonym of Palaeictops'
- 'Palaeictidops belongs to ' according to Winge 1917
- 'Palaeictops is a subjective synonym of Diacodon'
- 'Palaeictops belongs to Leptictidae' according to Matthew 1899
- 'Palaeosinopa lutreola belongs to Palaeosinopa'
- 'Paramys bicuspis is a subjective synonym of Paramys copei'
- 'Paramys bicuspis belongs to Paramys' according to Loomis 1907
- 'Paramys primaevus is a subjective synonym of Paramys copei'
- 'Paramys primaevus belongs to Paramys' according to Loomis 1907
- 'Paramys quadratus is a subjective synonym of Paramys major'
- 'Paramys quadratus belongs to Paramys' according to Loomis 1907
- 'Plagiomene belongs to Plagiomenidae'
- 'Plagiomene multicuspis belongs to Plagiomene'
- 'Plesiarctomys buccatus is recombined as Paramys buccatus'
- 'Prototomus insidiosus is recombined as Apheliscus insidiosus'
- 'Prototomus insidiosus belongs to Prototomus' according to Cope 1874
- 'Stypolophus bicuspis is recombined as Diacodon bicuspis'