Lobiger souverbii 
Loch's Chromodoris 
Lomanotus vermiformis 
Luria lurida 
Mangrove Periwinkle 
Map cowry 
Margarita Egg Cowry 
Margined Ram's-Horn 
Marianina rosea 
Marionia arborescens 
Marionia elongoviridis 
Marionia pustulosa 
Marten's Sidegill Slug 
Mask Limpet 
Mediterranean Limpet 
Mediterranean Violet Aeolid 
Megaustenia heliciformis 
Meghimatium pictum 
Melarhaphe neritoides 
Melibe coralophilia 
Melibe engeli 
Melibe papillosa 
Melibe viridis 
Melo broderipii