Theceurybia gaudichaudii – synonym of Hydromyles globulosa
Theceurybia norfolkensis – synonym of Hydromyles globulosa
Thielea procera – synonym of Limacina helicoides
Thilea procera – synonym of Limacina helicoides
Thliptodon akatsukai – synonym of Thliptodon akatukai
Thliptodon atlanticus – synonym of Thliptodon gegenbauri
Thliptodon rotundatus – synonym of Thliptodon antarcticus
Tholapex solutum – synonym of Firoloida desmaresti
Tiedemannia chrysosticta – synonym of Gleba chrysostricta
Tiedemannia creniptera – synonym of Gleba cordata
Tiedemannia hyalina? – synonym of Gleba cordata
Tiedemannia napolitana – synonym of Gleba cordata
Tiedemannia neapolitana – synonym of Gleba cordata
Tiedemannia punctata – synonym of Gleba chrysostricta
Tiedemannia punctata? – synonym of Desmopterus papilio
Trichocyclus dumerili? – synonym of Spongiobranchaea australis
Trichocyclus dumerilii? – synonym of Spongiobranchaea australis