Luminous Organs and Lateral Line of Midshipman, _Porichthys notatus_. 192 Cross-section of Ventral Phosphorescent Organ of Midshipman, _Porichthys notatus_. 193 Section of Deeper Portion of Phosphorescent Organ, _Porichthys notatus_. 194 _Leptecheneis naucrates_, Sucking-fish or Pegador. 197 _Caularchus mæandricus_, Clingfish. 198 _Polistotrema stouti_, Hagfish. 199 _Pristis zysron_, Indian Sawfish. 200 _Pristiophorus japonicus_, Saw-shark. 201 Skeleton of Pike, _Esox lucius_. 203 Skeleton of Red Rockfish, _Sebastodes miniatus_. 214 Skeleton of a Spiny-rayed Fish of the Tropics, _Holacanthus ciliaris_. 214 Skeleton of the Cowfish, _Lactophrys tricornis_. 215 _Crystallias matsushimæ_, Liparid. 218 _Sebastichthys maliger_, Yellow-backed Rockfish. 218 _Myoxocephalus scorpius_, European Sculpin. 219 _Hemitripterus americanus_, Sea-raven. 220 _Cyclopterus lumpus_, Lumpfish. 220 _Psychrolutes paradoxus_, Sleek Sculpin. 221 _Pallasina barbata_, Agonoid-fish. 221 _Amblyopsis spelæus_, Blindfish of the Mammoth Cave. 221 _Lucifuga subterranea_, Blind Brotula. 222 _Hypsypops rubicunda_, Garibaldi. 227 _Synanceia verrucosa_, Gofu or Poison-fish. 229 _Alticus saliens_, Lizard-skipper. 230 _Etheostoma camurum_, Blue-breasted Darter. 231 _Liuranus semicinctus_ and _Chlevastes colubrinus_, Snake-eels. 233 Coral Reef at Apia. 234 _Rudarius ercodes_, Japanese Filefish. 241 _Tetraodon setosus_, Globefish. 244 _Dasyatis sabina_, Sting-ray. 246 _Diplesion blennioides_, Green-sided Darter. 247 _Hippocampus mohnikei_, Japanese Sea-horse. 250 _Archoplites interruptus_, Sacramento Perch. 258 Map of the Continents, Eocene Time. 270 _Caulophryne jordani_, Deep-sea Fish of Gulf Stream. 276 _Exerpes asper_, Fish of Rock-pools, Mexico. 276 _Xenocys jessiæ._ 279