Maccoys aclidid-shell (Austrorissopsis maccoyi)

Maccoy’s spindle-cowrie (Pellasimnia maccoyi)

Macleay’s sea-slug (Spurilla macleayi)

Macpherson’s false-turrid (Mitromorpha macphersonae)

Macpherson’s sea-slug (Phyllodesmium macphersonae)

Magellanic rock-whelk (Fusitriton magellanicus retiolus)

magpie volute-mitre (Waimatea obscura)

Maltese-cross limpet (Patelloida insignis)

mandarin whelk (Penion mandarinus)

mangrove air-breather (Ophicardelus ornatus)

many-angled watering-pot (Dianadema multiangularis)

many-fingered sea-slug (Crimora multidigitalis)

many-grooved dove-shell (Aesopus plurisulcatus)

many-grooved rice-shell (Onoba multilirata)

many-leafed trophon (Gemixystus polyphyllius)

many-ribbed dove-shell (Retizafra multicostata)

many-ribbed false-turrid (Mitromorpha multicostata)

many-spotted sea-slug (Chromodoris multimaculosa)

Maori octopus (Octopus maorum)

marbled sea-lemon (Alloiodoris marmorata)

Margarita’s sea-slug (Ercolania margaritae)

margined olive (Amalda marginata)

margin-like false-turrid (Marita compta)

Maria’s pyramid-shell (Turbonilla mariae)

Maria’s winkle (Laevilitorina mariae)

marked chiton (Bassethullia glypta)

mask pyramid-shell (Hinemoa tasmanica)

masked top-shell (Clanculus personatus)

Massy’s squid (Tetronychoteuthis massyae)

Matthews’ chiton (Plaxiphora matthewsi)

Matthewsian chiton (Leptochiton matthewsianus)

Mauge family’s sea-slug (Dendrodoris maugeana)

Maugean margin-shell (Dentimargo maugeana)

Maugean sea-slug (Melibe maugeana)

Mauger’s top-shell (Clanculus maugeri)

Mauge’s sea-slug (Onchidoris maugeansis)

Mawle’s beautiful chiton (Callistochiton mawlei)

Mawle’s chiton (Ischnochiton mawlei)

May’s beautiful chiton (Callochiton mayi)

May’s cap-limpet (Cocculinella mayi)

May’s chiton (Ischnochiton mayi)

May’s dog-cockle (Glycymeris mayi)

May’s false-turrid (Paramontana mayana)

May’s limpet (Notoacmea mayi)

May’s liotia (Munditia mayana)

May’s lucine (Myrtea mayi)

May’s margin-shell (Dentimargo mayii)

May’s nutlet-shell (Pronucula mayi)

May’s orbitestellid (Orbitestella mayi)

May’s pyramid-shell (Odostomia mayii)

May’s top-shell (Ethminolia probabilis)

May’s urchin-snail (Melanella mayi)

measled sea-slug (Eubranchus rubeolus)

melancholy squid (Sandalops melancholicus)

Mestayer’s whelk (Cumia mestayerae)

Metcalfe’s pyramid-shell (Syrnola metcalfei)

metella ark-shell (Barbatia metella)

Michael’s sea-slug (Hallaxa michaeli)

microscopic aclidid-shell (Aclis microscopica)

microscopic false-turrid (Nepotilla microscopica)

microscopic margin-shell (Balanetta microscopica)

mid-point sea-slug (Berthella medietas)

milk-stone venus (Venerupis galactites)

milky brittlestar-snail (Stilapex lactarius)

milky false-turrid (Filodrillia lacteola)

milky lepton (Mysella lactea)

milky lucine (Callucina lacteola)

milky nutmeg-shell (Cancellaria lactea)

milky-mouthed dove-shell (Pseudamycla miltostoma)

millet nut-shell (Ledella miliacea)

mimic false-turrid (Zenepos mimica)

minute aclidid-shell (Awanuia minutula)

minute false-turrid (Zenepos minuta)

minute pyramid-shell (Koloonella micra)

mitre-like false-turrid (Guraleus mitralis)

mitre-shaped volute (Lyria mitraeformis)

Mitsui’s sea-slug (Diaphorodoris mitsuii)

mixed limpet (Lottia mixta)

mixta margin-shell (Hydroginella mixta)

mobile dog-whelk (Nassarius mobilis)

modest sunset-shell (Gari modesta)

modest tellin (Abranda modestina)

Mörch’s wentletrap (Plastiscala morchi)

most-grainy false-turrid (Turrella granulosissima)

most-oblique condyl-clam (Propecuna obliquissima)

mown rice-shell (Onoba demessa)

mud ark-shell (Anadara trapezia)

Murat Bay rice-shell (Lucidestea muratensis)

Murray’s file-shell (Limea murrayi)

mussel drill (Bedeva paivae)

myodora-like thracia (Thracia myodoroides)