Chaetodiadema japonicum Mortensen, 1904 (original description)
Gymnechinus inconspicuus Mortensen, 1904 accepted as Nudechinus inconspicuus (Mortensen, 1904) (original description)
Gymnechinus pulchellus Mortensen, 1904 (original description)
Gymnechinus versicolor Mortensen, 1904 accepted as Desmechinus versicolor (Mortensen, 1904) (original description)
Hemipedina mirabilis Döderlein, 1885 accepted as Caenopedina mirabilis (Döderlein, 1885) (new combination reference)
Microcyphus annulatus Mortensen, 1904 (original description)
Opechinus spectabilis Mortensen, 1904 accepted as Erbechinus spectabilis (Mortensen, 1904) (original description)
Pleurechinus doederleini Mortensen, 1904 accepted as Paratrema doederleini (Mortensen, 1904) (original description)
Pleurechinus maculatus Mortensen, 1904 accepted as Temnotrema maculatum (Mortensen, 1904) (original description)
Pleurechinus scillae (Mazzeti, 1894) sensu Mortensen, 1904 accepted as Temnotrema reticulatum (Mortensen in de Meijere, 1904) (basis of record)
Pleurechinus siamensis Mortensen, 1904 accepted as Temnotrema siamense (Mortensen, 1904) (original description)
Pleurechinus siamensis pulchellus Mortensen, 1904 accepted as Temnotrema pulchellum (Mortensen, 1904) (original description)
Pleurechinus variegatus Mortensen, 1904 accepted as Temnotrema sculptum A. Agassiz, 1864 (original description)
Salmacis bicolor f. typica Mortensen, 1904 accepted as Salmacis bicolor typica Mortensen, 1904 † (original description)

 Etymology

 for Araeosoma owstoni Mortensen, 1904

Named after the collector of part of the type material, Mr. Owston (incorrectly spelled "Owsten" in the paper, but ... [details]

 Spelling

 for Araeosoma owsteni Mortensen, 1904

Spelling corrected from "owsteni" to "owstoni" in an Erratum published in the same volume (on an unpaginated page ... [details]