Mamestra, 79 " composita, 80 " mutans, 79 " ustistriga, 81 Mandibles, 2 Mantidæ, 109 Maxillae, 2 Mayflies, 105 Melampsalta, 118 Melolonthidæ, 26 Melolontha, 27 " vulgaris, 27 Mesothorax, 2 Mesonotum, 2 Mesosternum, 2 Metamorphosis, 4 Metablax, 29 " acutipennis, 29 Metathorax, 2 Migrations of ants, 37 Miltogramma, 59 " mestor?, 59 Mosquito, 40 Moths, 69 " setting, 12 Musca, 61 " cæsar, 61 " domestica, 61 Muscidæ, 59 Mycetophila, 46 " antarctica, 46 Myrmeleontidæ, 99 Nemocera, 40 Nemorea, 59 " nyctemerianus, 59 Nervous system, 4 Net, 11 Neuroptera, 7, 99 Nitidulidæ, 23 Noctuidæ, 77 Notonectidæ, 120 Notonecta, 121 " glauca, 121 Nyctemera, 73 " annulata, 73 Nymphalidæ, 65 Oeceticus, 74 " omnivorus, 74 Oecophora, 97 " scholæa, 97 Oedipoda, 115 " cinerascens, 115 Oestridæ, 63 Oestrus, 63 " perplexus, 63 Ochrocydus, 31 " huttoni, 31 Orders, 5 Oreda, 31 " notata, 31 Orthoptera, 7, 103 Ovipositor, 38 Oxyethira, 99 " albiceps, 99