Eryonidæ, 135 Eyes of abysmal animals, 67 —— of deep-sea crustacea, 72 —— of deep-sea fish, 69 —— of deep-sea mollusca, 71 —— of _Genityllis_, 118 —— of _Neobythites_, 69 —— of _Serolis_, 73 _Fenja_, 15 ‘Fish Hawk,’ American vessel, 12 Fol and Sarasin’s experiments, 25 Foraminifera, 90 Forbes, on the probable existence of a deep-sea fauna, 2 —— on zones of distribution, 49 Ganoidei, 149 Gasteropoda, 119 Gephyrea, 116 Gills of deep-sea fish, 151 Globerigina ooze, discovery of, 5 —— distribution and composition of, 37 Green mud, 42 Gunn, Dr., on the eyes of _Genityllis_, 118 Günther, Dr., on deep-sea fish, 150 Hall, Marshall, 12 Halosauridæ, 164 ‘Hassler,’ American ship, 12 Herdman, on Ascidians, 143, 146 Hermit crabs, 139 Hoek, Dr., on Cirripedia, 132 —— on Pycnogonida, 140 Holothuridea, 106 Hoyle, on Cephalopoda, 120 Hydroids, 92 ‘Investigator,’ H.M.S., 16 _Ipnops Murrayi_, colour of, 60, 61 _Ipnops Murrayi_, phosphorescent organs of, 160 Isopoda, 127 Katantic sub-zone, 50 ‘Knight Errant,’ H.M.S., 12 Lamellibranchia, 119 ‘Lightning,’ H.M.S., 8, 9 Lime, scarcity of, in bones of bathybial fish, 83 —— in shells of mollusca, 83 Littoral sub-zone, 49 Lycodidæ, 155 Macrura, 135 Macruridæ, 156 Madreporaria, 94 Medusæ, 91 Mollusca, 119 —— colour of, 62 Moore, Capt., 94 Moseley, H. N., on colour of Cœlentera, 65 —— on phosphorescent organs of _Ipnops_, 160 —— on the darkness of the abyss, 22 —— on the phosphorescence of Alcyonarians, 25 Murray, on _Bathypterois_, 159 Nekton, 53 Neritic zone, 48 ‘Norma,’ Mr. Hall’s yacht, 12 Norske Nord-havns expedition, 7, 15 Ophidiidæ, 156 Ostracoda, 123 Packard, on the illumination of the abyss, 23 Pediculati, 155 Pelagic zone, 47 Pennatulidæ, 96 _Phoronis_, 111 Phosphorescence of Alcyonarians, 81 — of deep-sea Crustacea, 80 — of Echinoderma, 81 Phosphorescent light in the abyss, 24 — organs of deep-sea fish, 77 Pigment in mucous membranes of deep-sea fish, 84, 152 Plankton, 52 Pleuronectidæ, 157 Polar currents, 30, 33 Polychæta, 118 ‘Porcupine,’ H.M.S., 8, 9 Porifera, 91 Pourtales, Count, 10 Pressure in the abyss, 19 Protozoa, 88 Pteropod ooze, 39 Pycnogonida, 139 Radiolaria, 89 Radiolarian ooze, 39 Red mud, 37 — — off the Brazilian coasts, 42 _Rhabdopleura_, 111 Ross, Sir James, on the fauna of the deep sea, 3 Salmonidæ, 163 Sargasso sub-zone, 48 Sars, 6, 9, — on Amphipoda, 125 — on _Brisinga_, 105 Schizopoda, 133 Scopelidæ, 158 _Serolis_, 127 Siphonophora, 92 Size of deep-sea animals, 85 — of fish, 153 Smith, Mr., on Lamellibranchia, 119 Spatangoids, 101 Sponges, 91 Stebbing, Rev. T. R., on Amphipoda, 125 Sternoptychidæ, 158 Stomatopoda, 133 Stomiatidæ, 162 ‘Talisman,’ French vessel, 12 Teleostei, 149, 154 Temperature of the abyss, 28