Opinions from O. Abel 1938
- 'Aulocetus calaritanus is recombined as Cetotheriopsis calaritanus'
- 'Aulocetus lovisati [misspelled as Aulocetus lovisatoi] belongs to Aulocetus'
- 'Aulocetus sammarinensis belongs to Aulocetus'
- 'Balaena palaeatlantica is recombined as Rhegnopsis palaeatlanticus'
- 'Balaena prisca is recombined as Siphonocetus priscus'
- 'Balaenodon lintianus is recombined as Cetotheriopsis lintianus'
- 'Balaenoptera ryani belongs to Balaenoptera'
- 'Balaenoptera sursiplana belongs to Balaenoptera'
- 'Cephalotropis coronatus belongs to Cephalotropis'
- 'Cetotherium furlongi belongs to Cetotherium'
- 'Cetotherium helmersenii belongs to Cetotherium'
- 'Cetotherium megalophysum is recombined as Plesiocetopsis megalophysum'
- 'Cetotherium moreni [misspelled as Aglaocetus morenoi] belongs to Aglaocetus'
- 'Cetotherium rathkii is corrected as Cetotherium rathkei and belongs to Cetotherium'
- 'Cophocetus oregonensis belongs to Cophocetus'
- 'Eschrichtius cephalus is recombined as Cetotherium cephalum'
- 'Eschrichtius leptocentrus is recombined as Cetotherium leptocentrum'
- 'Eschrichtius polyporus is recombined as Cetotherium polyporum'
- 'Herpetocetus scaldiensis belongs to Herpetocetus'
- 'Isocetus depauwii is corrected as Isocetus depauwi and belongs to Isocetus'
- 'Megaptera expansa is recombined as Siphonocetus expansus'
- 'Megaptera miocaena belongs to Megaptera'
- 'Mesocetus hungaricus belongs to Mesocetus'
- 'Mesocetus latifrons belongs to Mesocetus'
- 'Mesocetus longirostris belongs to Mesocetus'
- 'Mesocetus pinguis belongs to Mesocetus'
- 'Mesocetus siphunculus belongs to Mesocetus'
- 'Mesoteras kerrianus belongs to Mesoteras'
- 'Metopocetus durinasus belongs to Metopocetus'
- 'Mixocetus elysius belongs to Mixocetus'
- 'Parietobalaena palmeri belongs to Parietobalaena'
- 'Parietobalaena securis belongs to Parietobalaena'
- 'Peripolocetus vexillifer belongs to Peripolocetus'
- 'Plesiocetus dyticus is recombined as Cetotheriopsis dyticus'
- 'Plesiocetus notopelagicus is recombined as Mesocetus notopelagicus'
- 'Siphonocetus clarkianus belongs to Siphonocetus'
- 'Tiphyocetus temblorensis belongs to Tiphyocetus'
- 'Tretulias buccatus belongs to Tretulias'
- 'Ulias moratus belongs to Ulias'