Opinions from E. C. Case 1904
- 'Archaeoceti belongs to Cetacea'
- 'Aves belongs to Vertebrata'
- 'Balaena belongs to Balaenidae'
- 'Balaena affinis belongs to Balaena'
- 'Balaena prisca is recombined as Siphonocetus priscus'
- 'Balaenoptera belongs to Balaenidae'
- 'Balaenoptera pusilla is replaced by Cetotherium parvum'
- 'Balaenoptera sursiplana belongs to Balaenoptera'
- 'Balanadae is corrected as Balaenidae and belongs to Mysticoceti'
- 'Cephalotropis belongs to Balaenidae'
- 'Cephalotropis coronatus belongs to Cephalotropis'
- 'Cetacea belongs to Mammalia'
- 'Cetophis belongs to Platanistidae'
- 'Cetophis heteroclitus belongs to Cetophis'
- 'Cetotherium belongs to Balaenidae'
- 'Cetotherium megalophysum belongs to Cetotherium'
- 'Cetotherium parvum belongs to Cetotherium'
- 'Chelonii is corrected as Chelonia and belongs to Reptilia'
- 'Crocodilia belongs to Reptilia'
- 'Crocodylidae [misspelled as Crocodilidae] belongs to Eusuchia'
- 'Cryptodira belongs to Chelonia'
- 'Cynorca proterva is recombined as Squalodon protervus'
- 'Delphinapterus gabbii is recombined as Priscodelphinus gabbii'
- 'Delphinapterus lacertosus is recombined as Priscodelphinus lacertosus'
- 'Delphinapterus ruschenbergeri is recombined as Priscodelphinus ruschenbergeri'
- 'Delphinidae belongs to Odontoceti'
- 'Delphinodon belongs to Platanistidae'
- 'Delphinus calvertensis is recombined as Lophocetus calvertensis'
- 'Delphinus conradi is recombined as Ixacanthus conradi'
- 'Eschrichtius cephalus is recombined as Cetotherium cephalum'
- 'Eusuchia belongs to Crocodilia'
- 'Hypocetus belongs to Physeteridae'
- 'Ixacanthus belongs to Platanistidae'
- 'Ixacanthus coelospondylus belongs to Ixacanthus'
- 'Lophocetus belongs to Platanistidae'
- 'Macrophoca atlantica is recombined as Squalodon atlantica'
- 'Mammalia belongs to Vertebrata'
- 'Manatidae belongs to Sirenia'
- 'Manatus giganteus is recombined as Trichechus giganteus'
- 'Megaptera expansa is recombined as Siphonocetus expansus'
- 'Metopocetus belongs to Balaenidae'
- 'Metopocetus durinasus belongs to Metopocetus'
- 'Mystacoceti [misspelled as Mysticoceti] belongs to Cetacea'
- 'Odontoceti belongs to Cetacea'
- 'Orycterocetus belongs to Physeteridae'
- 'Orycterocetus cornutidens is a subjective synonym of Orycterocetus crocodilinus'
- 'Paracetus mediatlanticus is recombined as Hypocetus atlanticus'
- 'Phoca wymani belongs to Phoca'
- 'Physeteridae belongs to Odontoceti'
- 'Platanistina was reranked as the family Platanistidae and belongs to Odontoceti'
- 'Priscodelphinus belongs to Platanistidae'
- 'Priscodelphinus atropius is recombined as Ixacanthus atropius'
- 'Priscodelphinus crassangulum belongs to Priscodelphinus'
- 'Priscodelphinus grandaevus belongs to Priscodelphinus'
- 'Priscodelphinus spinosus is recombined as Ixacanthus spinosus'
- 'Priscodelphinus stenus is recombined as Ixacanthus stenus'
- 'Procellariidae belongs to Tubinares'
- 'Puffinus belongs to Procellariidae'
- 'Puffinus conradi belongs to Puffinus'
- 'Reptilia belongs to Vertebrata'
- 'Rhabdosteus belongs to Platanistidae'
- 'Rhabdosteus latiradix belongs to Rhabdosteus'
- 'Sastrilophus dehmi is a nomen dubium'
- 'Selachii belongs to Elasmobranchii'
- 'Siphonocetus belongs to Balaenidae'
- 'Siphonocetus clarkianus belongs to Siphonocetus'
- 'Sirenia was reranked as a order and belongs to Mammalia'
- 'Squalodon belongs to Squalodontidae'
- 'Squalodon mento is recombined as Delphinodon mento'
- 'Squalodontidae belongs to Odontoceti'
- 'Squatina belongs to Squatinidae'
- 'Squatina occidentalis belongs to Squatina'
- 'Squatinidae belongs to Tectospondyli'
- 'Steganopodes belongs to Aves'
- 'Sula loxostyla belongs to Sula'
- 'Sulidae belongs to Steganopodes'
- 'Tectospondyli belongs to Selachii'
- 'Thecachampsa sericodon belongs to Thecachampsa'
- 'Tretosphys uraeus is recombined as Priscodelphinus uraeus'
- 'Tretulias belongs to Balaenidae'
- 'Tretulias buccatus belongs to Tretulias'
- 'Trichechus belongs to Manatidae'
- 'Trionyx belongs to Trionychia'
- 'Trionyx cellulosus belongs to Trionyx'
- 'Tubinares belongs to Aves'
- 'Ulias belongs to Balaenidae'
- 'Ulias moratus belongs to Ulias'
- 'Zarhachis belongs to Platanistidae'
- 'Zarhachis flagellator belongs to Zarhachis'
- 'Zarhachis tysonii belongs to Zarhachis'
- 'Zeuglodontidae belongs to Archaeoceti'