- icarus Bayle, 1880 = Cacozeliana icarus (family Cerithiidae – Bittiinae)

- illecebrosus Iredale, 1925 = Scaphander illecebrosus (family Cylichnidae)

- illevis Hedley, 1913 = Poromya illevis (family Poromyidae – Poromyinae)

- illibrata Verco, 1906 = Asteracmea illibrata (family Lottiidae – Lottiinae)

- imbricata Gray, 1839 = Bembicium auratum (family Littorinidae – Lacuninae)

- imbricata Lamarck, 1816 = Granata imbricata (family Trochidae – Eucyclinae)

- immaculata Pritchard & Gatliff, 1900 = Apicalia brazieri (family Eulimidae)

- immaculata Tenison Woods, 1876 = Dosinia sculpta (family Veneridae – Dosiniinae)

- immaculata Tenison Woods, 1877 = Munditia subquadrata (family Liotiidae – Liotiinae)

- immaculatus Tenison Woods, 1876 = Paracuneus immaculatus (family Drillidae)

- immersa Angas, 1865 = Maoricrypta immersa (family Calyptraeidae)

- immunitus Iredale, 1936 = Chicoreus denudatus (family Muricidae – Muricinae)

- impactus Hermann, 1782 = Musculus impactus (family Mytilidae)

- imperator Chun, 1908 = Chiroteuthis imperator (family Chiroteuthidae)

- imperforata Ponder & Yoo, 1977 = Rissoella imperforata (family Rissoellidae)

- imperialis Angas, 1864 = Plocamopherus imperialis (family Polyceridae – Triophinae)

- impertusa Burrow, 1815 = Stomatella impertusa (family Trochidae – Stomatellinae)

- improbula Iredale, 1924 = Haliotis rubra (family Haliotidae)

- improrsa Laseron, 1956 = Badepigrus badia (family Anabathridae)

- inaequidens May, 1912 = Cystiscus halli (family Cystiscidae – Cystiscinae)

- incei Philippi, 1853 = Polinices incei (family Naticidae – Naticinae)

- incerta Tenison Woods, 1876 = Munditia tasmanica (family Liotiidae – Liotiinae)

- incertum Reeve, 1863 = Astele incertum (family Calliostomatidae – Calliostomatinae)

- incertus May, 1919 = Cystiscus incertus (family Cystiscidae – Cystiscinae)

- incidatus Frauenfeld, 1867 = Amphithalamus incidatus (family Anabathridae)

- incii Reeve, 1850 = Diodora lineata (family Fissurellidae – Emarginulinae)

- incinctus Fenaux, 1942 = Conus anemone (family Conidae – Coninae)

- incisura A. Adams, 1853 = Emarginula incisura (family Fissurellidae – Emarginulinae)

- incola Burn, 1974 = Cerberilla incola (family Aeolidiidae)

- incompleta Hedley, 1908 = Pusillina discrepans (family Rissoidae – Rissoinae)

- inconspicua Pritchard & Gatliff, 1902 = Terebra tristis (family Terebridae – Terebrinae)

- inconspicua Sowerby, 1846 = Mesoginella inconspicua (family Marginellidae – Marginellinae)

- inconstans Dunker, 1856 = Limnoperna inconstans (family Mytilidae)

- incrustus Tenison Woods, 1877 = Guraleus incrustus (family Conidae – Mangeliinae)

- indecora Burn, 1958 non Bergh, 1905 = Hallaxa michaeli (family Actinocyclidae)

- indiscreta Tate, 1898 = Curveulima indiscreta (family Eulimidae)

- indiscretus May, 1911 = Cystiscus indiscretus (family Cystiscidae – Cystiscinae)

- inermis Robson, 1926 = Lycoteuthis lorigera (family Lycoteuthidae)

- infelix Jousseaume, 1857 = Mesoginella olivella (family Marginellidae – Marginellinae)

- infelix Webster, 1906 = Bouchetriphora pallida (family Triphoridae – Triphorinae)

- infernalis Chun, 1903 = Vampyroteuthis infernalis (family Vampyroteuthidae)

- inflata d’Orbigny, 1836 = Limacina inflata (family Limacinidae)

- inflata Tate & May, 1900 = Melanella inflata (family Eulimidae)

- inflexa Lesueur, 1813 = Cavolinia inflexa (family Cavoliniidae – Cavoliniinae)

- infumata Crosse, 1863 = Mitrella austrina (family Columbellidae – Atiliinae)

- ingens Smith, 1881 = Moroteuthis ingens (family Onychoteuthidae)

- injussa Iredale, 1931 = Solatisonax injussa (family Architectonicidae – Architectonicinae)

- innotabilis Hedley, 1903 = Hedleytriphora innotabilis (family Triphoridae – Triphorinae)

- inornata Tenison Woods, 1881 = Eudoxochiton inornata (family Ischnochitonidae – Callochitoninae)

- inscriptum Tate, 1899 = Zalipais inscriptum (family Turbinidae – Skeneinae)

- insculptum Reeve, 1865 = Batillariella estuarina (family Batillariidae)

- insignis May, 1911 = Seila insignis (family Cerithiopsidae – Seilinae)

- insignis Menke, 1843 = Patelloida insignis (family Lottiidae – Patelloidinae)

- insignis Pilsbry, 1906 = Tucetona sordida (family Glycymerididae)

- insperata Iredale, 1927 = Semicassis labiata (family Tonnidae – Phaliinae)

- instar Iredale, 1925 = Zygochlamys delicatula (family Pectinidae – Chlamydinae)

- intermedia Ashby, 1927 = Plaxiphora matthewsi (family Mopaliidae)

- interrupta Angas, 1865 = Anachis interrupta (family Columbellidae – Atiliinae)

- invalida Verco, 1909 = Plastiscala invalida (family Epitoniidae)

- ione Gray, 1850 = Pododesmus zelandicus (family Anomiidae – Placunanomiinae)

- iravadioides Gatliff & Gabriel, 1913 = Microdryas iravadioides (family Anabathridae)

- iredalei Ashby, 1923 = Cryptoplax iredalei (family Cryptoplacidae)

- iredalei Cotton, 1930 = Notocorbula stolata (family Corbulidae – Corbulinae)

- iredalei Cotton, 1931 = Myadora albida (family Myochamidae)

- iredalei Dupuis, 1918 = Ischnochiton lineolatus (family Ischnochitonidae – Ischnochitoninae)

- iredalei Finlay, 1927 = Gazameda iredalei (family Turritellidae – Turritellinae)

- iredalei May, 1919 = Orbitestella iredalei (family Orbitestellidae)

- iridescens Tate, 1889 = Venerupis iridescens (family Veneridae – Tapetinae)

- iriodon Philippi, 1845 = Phasianotrochus irisodontes (family Trochidae – Trochinae)

- irisodontes Quoy & Gaimard, 1834 = Phasianotrochus irisodontes (family Trochidae – Trochinae)

- irrorata Reeve, 1859 = Mitrella irrorata (family Columbellidae – Atiliinae)

- ischna Tate, 1899 = Epigrus cylindraceus (family Epigridae)