Opinions from J. F. Brandt 1874
- 'Arionius servatus is replaced by Squalodon meyeri'
- 'Balaena belongs to Balaenidae'
- 'Cetotherium (Cetotheriophanes) cortesii is a subjective synonym of Balaenoptera cuvieri'
- 'Balaena emarginata is recombined as Balaenodon emarginatus'
- 'Balaena prisca is a subjective synonym of Balaena mysticetus'
- 'Balaena tannenbergensis is a subjective synonym of Balaena mysticetus'
- 'Balaenodon lintianus is recombined as Cetotheriopsis linziana'
- 'Balaenoidorum belongs to Cetacea'
- 'Balaenoptera belongs to Balaenopterinae'
- 'Balaenoptera robusta is recombined as Plesiocetus robustus'
- 'Balaenopteridae belongs to Balaenoidorum'
- 'Balaenopterinae belongs to Balaenopteridae'
- 'Balanadae is corrected as Balaenidae and belongs to Balaenoidorum'
- 'Cetotheriinae [misspelled as Cetotherinae] belongs to Balaenopteridae'
- 'Cetotheriopsis belongs to Cetotherinae'
- 'Cetotherium belongs to Cetotherinae'
- 'Cetotherium (Cetotheriophanes) capellinii is a subjective synonym of Balaenoptera cuvieri'
- 'Cetotherium (Cetotheriophanes) cuvieri is a subjective synonym of Balaenoptera cuvieri'
- 'Champsodelphis belongs to Platanistinae'
- 'Champsodelphis acutus belongs to Champsodelphis'
- 'Champsodelphis letochae belongs to Champsodelphis'
- 'Champsodelphis macrognathus belongs to Champsodelphis'
- 'Champsodelphis valenciennesii is a subjective synonym of Champsodelphis macrogenius'
- 'Delphinapterus belongs to Phocaeninae'
- 'Delphininae belongs to Holodontidae'
- 'Delphinus belongs to Delphininae'
- 'Delphinus dationum belongs to Delphinus'
- 'Delphinus lophogenius is recombined as Champsodelphis lophogenius'
- 'Delphinus stenorhynchus belongs to Delphinus'
- 'Delphinus sulcatus is recombined as Schizodelphis sulcatus'
- 'Gymnorhinidae belongs to Odontocetoidorum'
- 'Holodontidae belongs to Odontocetoidorum'
- 'Balaena svendenborgii is a subjective synonym of Balaena mysticetus'
- 'Hypognathodontidae belongs to Odontocetoidorum'
- 'Macrochirifer vindobonensis belongs to Macrochirifer'
- 'Pachyacanthus belongs to Cetotherinae'
- 'Pachyacanthus letochae belongs to Pachyacanthus'
- 'Phocodon scillae is recombined as Squalodon scillae'
- 'Phocoeninae is corrected as Phocaeninae and belongs to Holodontidae'
- 'Platanistinae belongs to Holodontidae'
- 'Rhizoprion bariensis is recombined as Squalodon bariensis'
- 'Schizodelphis belongs to Platanistinae'
- 'Squalodon belongs to Gymnorhinidae'
- 'Squalodon antverpiensis belongs to Squalodon'
- 'Squalodon ehrlichii belongs to Squalodon'
- 'Squalodon gervaisii belongs to Squalodon'
- 'Squalodon grateloupii belongs to Squalodon'
- 'Squalodon hypsispondylus belongs to Squalodon'
- 'Squalodon incertus belongs to Squalodon'
- 'Squalodon meyeri belongs to Squalodon'
- 'Steno belongs to Delphininae'
- 'Steno gastaldii belongs to Steno'
- 'Zeuglodon belongs to Gymnorhinidae'
- 'Zeuglodon vasconum belongs to Zeuglodon'
- 'Ziphiinae belongs to Hypognathodontidae'