Halia flemingiana – synonym of Liomesus ovum
Hanleya dalli – synonym of Hanleya hanleyi
Hanleya debilis – synonym of Hanleya hanleyi
Hedylopsis brambelli – synonym of Asperspina brambelli
Helcion pellucidum – synonym of Ansates pellucida
Helix depressa – synonym of Skeneopsis planorbis
Helix labiosa – synonym of Rissoa membranacea
Helix lacuna – synonym of Lacuna parva
Helix laevigata – synonym of Velutina velutina
Helix margarita – synonym of Margarites helicinus
Helix neritoidea – synonym of Lamellaria perspicua
Helix perspicua – synonym of Lamellaria perspicua
Helix petraea – synonym of Melaraphe neritoides
Helix planorbis – synonym of Skeneopsis planorbis
Helix serpuloides – synonym of Skenea serpuloides
Helix stagnalis – synonym of Semisalsa stagnorum
Helix stagnorum – synonym of Semisalsa stagnorum
Helix subcarinata – synonym of Tornus subcarinatus
Hermaea brevicornis – synonym of Placida dendritica
Hermaea dendritica – synonym of Hermaea bifida
Hermaea dendritica – synonym of Placida dendritica
Hermaea hancockii – synonym of Hermaea bifida
Hermaea lutescens – synonym of Placida dendritica
Hermaea orbicularis – synonym of Placida dendritica
Hermaea ornata – synonym of Placida dendritica
Hermaea venosa – synonym of Placida dendritica
Hermania catena – synonym of Philine catena
Hero formosa arborescens – synonym of Hero formosa
Hiatella biaperta – synonym of Hiatella arctica
Hiatella gallicana – synonym of Hiatella arctica
Hiatella monoperta – synonym of Hiatella arctica
Hiatella oblonga – synonym of Hiatella arctica
Hiatella rugosa – synonym of Hiatella arctica
Hinia incrassata – synonym of Nassarius incrassatus
Hinia pygmaea – synonym of Nassarius pygmaeus
Hinia reticulata – synonym of Nassarius reticulatus
Hinia varicosa paucicostata – synonym of Nassarius pygmaeus
Hinnites distortus – synonym of Crassadoma pusio
Homalogyra atomus var. polyzona – synonym of Omalogyra atomus
Homalogyra atomus var. vitrea – synonym of Omalogyra atomus
Homalogyra rota margaritifera – synonym of Ammonicera rota
Homalogyra rotata – synonym of Ammonicera rota
Hyala mediterranea – synonym of Hyala vitrea
Hydrobia aponensis – synonym of Semisalsa stagnorum
Hydrobia confusa – synonym of Mercuria confusa
Hydrobia gracilis – synonym of Semisalsa stagnorum
Hydrobia minuta – synonym of Hydrobia neglecta
Hydrobia peracuta – synonym of Semisalsa stagnorum
Hydrobia procera – synonym of Semisalsa stagnorum
Hydrobia scamandri – synonym of Semisalsa stagnorum
Hydrobia stagnalis – synonym of Semisalsa stagnorum
Hydrobia stagnorum – synonym of Semisalsa stagnorum
Hydrobia ventrosa – synonym of Ventrosia ventrosa
Hypogaea barbata – synonym of Hiatella arctica
Hypogaea rhomboides – synonym of Hiatella arctica
Hypogaea verrucosa – synonym of Pholas dactylus