Gadfly, 112 Galathea spinirostris on Comatula, 20, 61 Gammarus of Avicula, 33 Gebia, 28 Gerardia Lamarckii, 49 Glossina morsitans, 119 Gnats, 116 Gordius, 153 ---- bifurcus, 180 ---- Indian, 180 ---- ornatus, 153 Gregarinæ, 160 Guinea worm, 105, 158 Gyges branchialis, 145 Gyrodactyli, 261 Gyrodactylus elegans, 262 Gyropeltis, 74 Halichondria suberea, 63 Halodactylus, 62 Hematopinus tenuirostris, 129 Helmidasys, 47 Hemieuryale, 49 Hemioniscus, 60 Hemiptera, 262 Hemistomum alatum, 204 Heterodera Schachtii, 248 Heteroneidæ, 236 Heterosammia, 63 Heteroura androphora, 248 Hippoboscus, 175 Hirudineæ, 108 ---- of fishes, 109 ---- reptiles, 112 Histriobdella, 80 Holtenia Carpenteri, 50 Hopalocarcinus, 21 Hyalonema, 64 Hydrachna geographica, 136 Hydractiniæ, 27 Hyperinæ, 32 Hyperia Latreillii, 33 ---- galba, 33 Ichneumons, 163 Ichthyoxenus Jellinghausii, 31, 146 Iones, thoracicus, 145 Isopods, parasite, 143 Ixodes bovis, 134 ---- of the dog, 135 ---- reduvius, 134 ---- ricinus, 96, 142 Kakerlot, 23 Krätzmilben, 133 Laura, 152 Læmippa rubra, 152 Leeches, aquatic, 110 ---- land, 111 Lepidonotus cirratus, 44 Leposphilus, 147 Leptus autumnalis, 137 Leptodera, 154 ---- appendiculata, 248 ---- pellio, 248 Lernea branchialis, 151 Lerneans, 148 Lerneoniscus, 146 ---- nodicornis, 150 Lichnophora, 159 Lice of Bees, 171 Limosina, 136 Linguatula serrata, 231 Linguatulidæ, 134 Liothe pallidum, 71 272 Lithoscaspus, 21 Lipoptena of the Stag, 177 Loxostoma, 41 Lucilia hominivora, 120 Liriope, 28 Lysidice erythrocephala, 43 Macaco Worm, 175 Magilus, 39 Maia and Polypidom, 20 Malacobdella, 109 Maringouins, 116 Measled pork, 190 Meloë, 173 Meloïdeæ, 171 Melophagus of the Sheep, 177 Membranipora, 41 Mermis, 158 Messmates fixed, 53 ---- free, 4 Midges, 116 Mnemiopsis, 44 Mnestra parasites, 61 Modiola, 16 Modiolaria, 40 Monostomata, 201 Monostoma mutabile, 201 ---- bijugum, 201 ---- verrucosum, 191 Mosquitoes, 117 Musca hominivora, 119 Mutualists, 68 Myasis, 123 Myzobdella, 81 Myzostoma, 42 Nais, 114 Nebalia, 35 Nemertes carcinophilus, 46 Nemocera, 115 Nereis succinea, 42 ---- tethyeola, 43 Nirmus buteonivorus, 70 Nitzchia elegans, 259 Notonecta, 124 Notopterophorus, 151 Nycteribia, 123 Octobothrium merlangi, 261 Octocotyle lanceolata, 261 Odontobius, 45 OEga on Hyalonema, 30 OEstri, 172 Ollulanus tricuspis, 247, 250 Onchocotyle appendiculata, 261 Opalina, 79 Ophiocnemis obscura, 48 Ophioneurus, 169 Ophiothela, 48 Ornithomya, 121 Ostracion, 10 Ostracotheres tridaenæ, 17 Oxybeles lumbricoides, 7 Oxyuris brachyura, 248 ---- incurvata, 237 ---- vermicularis, 241