---- _latitans_ 84 ---- _picta_ 84 ---- _piratica_ 84 ---- _rapax_ 83 Mackerel 88 _Mactra_ 86 ---- _stultorum_ 87 Madrepores 54 Mammalia, colouration in 92 _Margarita catenata_ 87 Measles 39 Medusæ 52, 65 Melanism in insects 79 Meldola, Prof. R., on Melanism 79 _Melitæa artemis_ 43 ---- _athalia_ 43 Mimicry 3, 4 Mollusca 21 ---- colouration in 85 Monstrosities, antipathy to 32 _Morphinæ_ 72 _Morpho_ 4 _Murex_ 86 Muscles of insects 71 _Nectarinea chloropygea_ 90 Newman, Mr., on varieties of butterflies 77 Newts 89 Nitzsch on feather-tracts 91 Nudibranchs 85 _Nymphalidæ_ 74 Oak Egger Moth 30 Ocelli 47 Ocelot 93 _Oliva_ 86 Opaque colouring 53 Organ-pipe coral 54 Origin of animals and plants 36 ---- -- species 1 Orthopoecilism 78 Oxen 94 Painted Lady Butterfly 68 Pangenesis 12 _Papilio Ajax_ 79 ---- _machaon_ 43, 68, 76, 78 ---- ---- larva of 81 ---- _merope_ 30, 76, 80