Acmaea kuragiensis Yokoyama, 1920 accepted as Lepeta kuragiensis (Yokoyama, 1920) (original description)
Anomia nipponensis Yokoyama, 1920 accepted as Anomia cytaeum Gray, 1850 (original description)
Astarte hakodatensis Yokoyama, 1920 (original description)
Basterotia trapezium Yokoyama, 1920 accepted as Paramya recluzi (A. Adams, 1864) accepted as Basterotia recluzi (A. Adams, 1864) (original description)
Bembix convexiusculum Yokoyama, 1920 † accepted as Ginebis argenteonitens (Lischke, 1872) (original description)
Cadulus gordonis Yokoyama, 1920 † accepted as Ditrupa gracillima Grube, 1878 (original description)
Calliostoma cipangoanum Yokoyama, 1920 accepted as Calliostoma shinagawense cipangoanum Yokoyama, 1920 (original description)
Calliostoma sagamianum Yokoyama, 1920 accepted as Calliostoma consors (Lischke, 1872) accepted as Tristichotrochus consors (Lischke, 1872) (original description)
Chlorostoma miyatense Yokoyama, 1920 † accepted as Enida japonica A. Adams, 1860 (original description)
Crassatella oblongata Yokoyama, 1920 accepted as Indocrassatella oblongata (Yokoyama, 1920) (original description)
Crepidula orbella Yokoyama, 1920 accepted as Ergaea walshi (Reeve, 1859) (original description)
Cylichna braunsi Yokoyama, 1920 † accepted as Cylichna biplicata (A. Adams, 1850) (original description)
Cylichna musashiensis Yokoyama, 1920 accepted as Adamnestia japonica (A. Adams, 1862) accepted as Mnestia japonica (A. Adams, 1862) (original description)
Diplodonta gouldi Yokoyama, 1920 accepted as Zemysina gouldi (Yokoyama, 1920) (original description)
Emarginula fragilis Yokoyama, 1920 (original description)
Ervilia otsuensis Yokoyama, 1920 accepted as Coecella chinensis Deshayes, 1855 (original description)
Fenella orientalis Yokoyama, 1920 † accepted as Cerithidium fuscum (A. Adams, 1860) (original description)
Jouannetia japonica Yokoyama, 1920 accepted as Netastoma japonicum (Yokoyama, 1920) (original description)
Leda gordonis Yokoyama, 1920 accepted as Saccella gordonis (Yokoyama, 1920) (original description)
Leda ramsayi Yokoyama, 1920 accepted as Nuculana yokoyamai Kuroda, 1934 (original description)
Lima quantoensis Yokoyama, 1920 (original description)
Lima zushiensis Yokoyama, 1920 (original description)
Lucina spectabilis Yokoyama, 1920 accepted as Lucinoma spectabilis (Yokoyama, 1920) (original description)
Lucina yamakawai Yokoyama, 1920 † accepted as Liralucina plicatula (A. Adams, 1862) (original description)
Lutraria radiata Yokoyama, 1920 accepted as Lutraria sieboldii Reeve, 1854 (original description)
Mitra plicifera Yokoyama, 1920 † accepted as Exilia hilgendorfi (E. von Martens, 1897) (original description)
Nucula tokyoensis Yokoyama, 1920 (original description)
Odostomia (Odostomia) sublimpida Yokoyama, 1920 accepted as Odostomia sublimpida Yokoyama, 1920 (original description)
Odostomia sublimpida Yokoyama, 1920 (original description)
Ostrea musashiana Yokoyama, 1920 † accepted as Neopycnodonte cochlear (Poli, 1795) (original description)
Parallelodon obliquatus Yokoyama, 1920 accepted as Porterius dalli (E. A. Smith, 1885) (original description)
Pecten intuscostatus Yokoyama, 1920 accepted as Parvamussium intuscostatum (Yokoyama, 1920) (original description)
Pecten miurensis Yokoyama, 1920 † accepted as Mimachlamys miurensis (Yokoyama, 1920) † (original description)
Pecten naganumana Yokoyama, 1920 † accepted as Pecten naganumanus Yokoyama, 1920 † (original description)
Pectunculus nipponicus Yokoyama, 1920 accepted as Glycymeris rotunda (Dunker, 1882) (original description)
Pectunculus pilsbryi Yokoyama, 1920 accepted as Glycymeris pilsbryi (Yokoyama, 1920) (original description)
Pholadomya japonica Yokoyama, 1920 accepted as Barnea japonica (Yokoyama, 1920) (original description)
Pleurotoma (Drillia) pseudoprincipalis Yokoyama, 1920 accepted as Inquisitor pseudoprincipalis (Yokoyama, 1920) (original description)
Pleurotoma (Mangilia) miyatensis Yokoyama, 1920 accepted as Ophiodermella miyatensis (Yokoyama, 1920) (original description)
Plicatula naganumana Yokoyama, 1920 accepted as Pecten albicans (Schröter, 1802) (original description)
Ringicula musashiensis Yokoyama, 1920 accepted as Ringicula doliaris Gould, 1860 (original description)
Rissoina submercurialis Yokoyama, 1920 † (original description)
Rissoina zeltnerioides Yokoyama, 1920 † accepted as Schwartziella zeltnerioides (Yokoyama, 1920) (original description)
Saxicava orientalis Yokoyama, 1920 accepted as Hiatella arctica (Linnaeus, 1767) (original description)
Scalaria turriculoides Yokoyama, 1920 accepted as Cirsotrema turriculoides (Yokoyama, 1920) accepted as Cirsotrema bonum (Melvill, 1906) (original description)
Skenea nipponica Yokoyama, 1920 accepted as Lissotesta sobrina (A. Adams, 1861) (original description)
Solen gordonis Yokoyama, 1920 (original description)
Tellina miyatensis Yokoyama, 1920 accepted as Semelangulus miyatensis (Yokoyama, 1920) (original description)
Tellina vestalioides Yokoyama, 1920 accepted as Hanleyanus vestalioides (Yokoyama, 1920) (original description)
Trichotropis planicostata Yokoyama, 1920 † accepted as Vermeijia planicostata (Yokoyama, 1920) † (original description)
Triforis otsuensis Yokoyama, 1920 accepted as Bouchetriphora otsuensis (Yokoyama, 1920) (original description)
Trophon muricatoides Yokoyama, 1920 † accepted as Trophonofusus muricatoides (Yokoyama, 1920) (original description)
Trophon nipponicus Yokoyama, 1920 † accepted as Boreotrophon xestra Dall, 1918 (original description)
Turritella nipponica Yokoyama, 1920 † (original description)
Venericardia cipangoana Yokoyama, 1920 accepted as Megacardita ferruginosa (A. Adams & Reeve, 1850) (original description)
Woodia concentrica Yokoyama, 1920 accepted as Lucinoma annulata (Reeve, 1850) (original description)

Honshu for Pecten miurensis Yokoyama, 1920 † 
Honshu for Pecten naganumana Yokoyama, 1920 † 
Japan for Acmaea kuragiensis Yokoyama, 1920 
Japan for Trichotropis planicostata Yokoyama, 1920 † 
Japan for Turritella nipponica Yokoyama, 1920 † 
Miura for Chlorostoma miyatense Yokoyama, 1920 †