Opinions from H. B. Fell 1966
- 'Ancylocidaris belongs to Diadematoida'
- 'Araeosoma belongs to Echinothuriinae'
- 'Aspidodiademinae was reranked as the family Aspidodiadematidae and belongs to Diadematoida'
- 'Asthenosoma belongs to Echinothuriinae'
- 'Atlasaster is a subjective synonym of Pedina'
- 'Centrostephanus belongs to Diadematidae'
- 'Diadema belongs to Diadematidae'
- 'Diadematacea belongs to Euechinoidea'
- 'Diadematidae belongs to Diadematoida'
- 'Diadematoida belongs to Diadematacea'
- 'Diademopsis belongs to Pedinidae'
- 'Dumblea belongs to Pedinidae'
- 'Echinopedina belongs to Pedinidae'
- 'Echinothuria belongs to Echinothuriinae'
- 'Echinothurideae is corrected as Echinothurioida and belongs to Diadematacea'
- 'Echinothuriidae belongs to Echinothurioida'
- 'Echinothuriinae belongs to Echinothuriidae'
- 'Endeodiadema belongs to Diadematoida'
- 'Engelia belongs to Diadematoida'
- 'Eodiadema belongs to Diadematidae'
- 'Eosalenia belongs to Aspidodiadematidae'
- 'Farquharsonia belongs to Pedinoida'
- 'Hebertia is a subjective synonym of Echinopedina'
- 'Helodiadema belongs to Diadematoida'
- 'Hemipedina belongs to Pedinidae'
- 'Heterocidaridae belongs to Diadematacea'
- 'Heterocidaris belongs to Heterocidaridae'
- 'Heteropedina belongs to Diadematoida'
- 'Kierechinus belongs to Diadematidae'
- 'Leiopedina belongs to Pedinidae'
- 'Leptocidaris belongs to Pedinoida'
- 'Loriolipedina belongs to Pedinidae'
- 'Macrodiadema belongs to Diadematoida'
- 'Mesodiadema belongs to Diadematidae'
- 'Micropedina belongs to Pedinidae'
- 'Miocidaris (Serpianotiaris) was reranked as Serpianotiaris and belongs to Diadematacea'
- 'Palaeodiadema belongs to Diadematidae'
- 'Palaeopedina belongs to Pedinidae'
- 'Pedina belongs to Pedinidae'
- 'Pediniens was reranked as the family Pedinidae and belongs to Pedinoida'
- 'Pedinina was reranked as the order Pedinoida and belongs to Diadematacea'
- 'Pedinothuria belongs to Diadematidae'
- 'Pelanechinidae was reranked as the subfamily Pelanechininae and belongs to Echinothuriidae'
- 'Pelanechinus belongs to Pelanechininae'
- 'Phalacropedina belongs to Pedinidae'
- 'Phymopedina belongs to Pedinidae'
- 'Pileus belongs to Pygasteridae'
- 'Plesiechinus belongs to Pygasteridae'
- 'Pseudopedina belongs to Pedinidae'
- 'Pseudorthopsis belongs to Pedinidae'
- 'Pygaster belongs to Pygasteridae'
- 'Pygasteridae belongs to Pygasteroida'
- 'Pygasteroida belongs to Diadematacea'
- 'Stenechinus belongs to Pedinidae'
- 'Tiaridia belongs to Aspidodiadematidae'