| FIG. | | PAGE |
| 1. | The Common Lobster (Homarus gammarus), Female, from the Side | 7 |
| 2. | One of the Abdominal Somites of the Lobster, with its Appendages, separated and viewed from in Front | 9 |
| 3. | Third Maxilliped of Lobster | 11 |
| 4. | Walking Legs of Lobster | 12 |
| 5. | Appendages of Lobster in Front of Third Maxilliped | 13 |
| 6. | Dissection of Male Lobster, from the Side | 16 |
| 7. | Gills of the Lobster, exposed by cutting away the Side-flap of the Carapace (Branchiostegite) | 18 |
| 8. | First Larval Stage of the Common Lobster. × 4 | 28 |
| 9. | Side-view of Rostrum of (A) Common Lobster (Homarus gammarus) and (B) American Lobster (Homarus americanus) | 32 |
| 10. | The "Fairy Shrimp" (Chirocephalus diaphanus), Male. × 2 | 35 |
| 11. | Estheria obliqua, One of the Conchostraca | 36 |
| 12. | Daphnia pulex, a Common Species of "Water-flea." Much enlarged | 37 |
| 13. | Shells of Ostracoda. Much enlarged | 38 |
| 14. | Cyclops albidus, a Species of Copepod found in Fresh Water | 39 |
| 15. | Nebalia bipes. Enlarged | 44 |
| 16. | Mysis relicta, One of the Mysidacea. Enlarged | 47 |
| 17. | Gnathophausia willemoesii, One of the Deep-sea Mysidacea. Half Natural Size | 48 |
| 18. | Diastylis goodsiri, One of the Cumacea. Enlarged | 49 |
| 19. | Apseudes spinosus, One of the Tanaidacea. Enlarged | 50 |
| 20. | A Woodlouse (Porcellio scaber), One of the Isopoda. Enlarged | 51 |
| 21. | An Amphipod (Gammarus locusta). Enlarged | 53 |
| 22. | Two Species of Caprellidæ | 54 |
| 23. | Paracyamus boopis, the Whale-louse of the Humpback Whale | 55 |
| 24. | Meganyctiphanes norvegica, One of the Euphausiacea. Twice Natural Size | 56 |
| 25. | Larval Stages of the Common Shore Crab (Carcinus mænas—see Plate IX.) | 68 |
| 26. | Last Larval Stage of the Common Porcelain Crab (Porcellana longicornis—see Fig. 41, P. 113). × 9 | 70 |
| 27. | First Larval Stage of Munida rugosa (see Plate VI.) × 10 | 71 |
| 28. | The Phyllosoma Larva of the Common Spiny Lobster (Palinurus vulgaris—see Plate V.). Much enlarged | 72 |
| 29. | Larval Stages of the Prawn Penæus (see Plate IV.). × 45 | 74 |
| 30. | Newly-hatched Young of a Crayfish (Astacus fluviatilis). Enlarged | 76 |
| 31. | Young Specimen of an African River Crab (Potamon johnstoni), taken from the Abdomen of the Mother. Much enlarged | 78 |
| 32. | Early Larval Stage of a Species of Squilla, probably S. dubia. × 10 | 80 |
| 33. | Larval Stages of the Brine Shrimp (Artemia salina) | 81 |
| 34. | Early Nauplius Larva of a Copepod (Cyclops). Much enlarged | 82 |
| 35. | Larval Stages of the Common Rock Barnacle (Balanus balanoides—see Plate III.) | 83 |
| 36. | A Common Hermit Crab (Eupagurus bernhardus) removed from the Shell | 91 |
| 37. | Pylocheles miersii, a Symmetrical Hermit Crab | 94 |
| 38. | Callianassa stebbingi (Female), a Sand-burrowing Thalassinid from the South Coast of England. Natural Size | 103 |
| 39. | The Common Sand-hopper (Talitrus saltator), Male, from the Side. × 3 | 108 |
| 40. | A, a Piece of a Tropical Sea-weed (Halimeda); B, a Crab (Huenia proteus) which lives among the Fronds of Halimeda, and closely resembles them in Form and Colour. Reduced | 110 |
| 41. | The Common Porcelain Crab (Porcellana longicornis), slightly enlarged, and One of the Third Maxillipeds detached and further enlarged to show the Fringe of Long Hairs | 113 |
| 42. | A Deep-sea Lobster (Nephropsis stewartii), from the Bay of Bengal. Reduced | 122 |
| 43. | Munidopsis regia, a Deep-sea Galatheid from the Bay of Bengal. Reduced | 123 |
| 44. | Thaumastocheles zaleucus. Reduced | 129 |
| 45. | A Deep-sea Crab (Platymaia wyville-thomsoni.) Reduced | 131 |
| 46. | Polycheles phosphorus, One of the Eryonidea, Female, from the Indian Seas | 133 |
| 47. | Eryon propinquus, One of the Fossil Eryonidea, from the Jurassic Rocks of Solenhofen | 135 |
| 48. | Conchœcia curta, an Ostracod of the Plankton. × 40 | 144 |
| 49. | Mimonectes loveni. A Female Specimen seen from the Side and from Below, showing the Distended-balloon-like Form of the Anterior Part of the Body. × 3 | 145 |
| 50. | The Zoëa Larva of a Species of Sergestes, taken by the "Challenger" Expedition. × 25 | 146 |
| 51. | The Nauplius Larva of a Species of Barnacle of the Family Lepadidæ, showing greatly-developed Spines. From a Specimen taken in the Atlantic Ocean, near Madeira. × 11 | 147 |
| 52. | Calocalanus pavo, One of the Free-swimming Copepoda of the Plankton. Enlarged | 148 |
| 53. | Copilia quadrata (Female), a Copepod of the Family Corycæidæ, showing the Pair of Large "Telescopic" Eyes. × 20 | 153 |
| 54. | Phronima colletti, Male. From a Specimen taken in Deep Water near the Canary Islands. × 12 | 154 |
| 55. | The Brine Shrimp (Artemia salina) | 164 |
| 56. | Chydorus sphæricus, a Common Species of Water-flea. × 50 | 166 |
| 57. | A Water-flea (Daphnia pulex), Female, with Ephippium containing Two "Resting Eggs." × 20 | 167 |
| 58. | Bythotrephes longimanus, Female, with Embryos in the Brood-sac. × 12 | 169 |
| 59. | Diaptomus cœruleus, Female. × 25 | 171 |
| 60. | Asellus aquaticus, Female. × 4 | 173 |
| 61. | Map showing the Distribution of Crayfishes | 175 |
| 62. | A Well Shrimp (Niphargus aquilex). × 7. | 185 |
| 63. | The Sea-slater (Ligia oceanica). About Twice Natural Size | 200 |
| 64. | Structure of the Breathing Organs of Porcellio scaber | 202 |
| 65. | Armadillidium vulgare. × 2½ | 203 |
| 66. | Two Branches of a Coral (Seriatopora) showing "Galls" inhabited by the Crab Hapalocarcinus marsupialis. On the Right the Female Crab, extracted from the Gall and further enlarged | 211 |
| 67. | Hyperia galba, Female. Enlarged | 213 |
| 68. | A, The Crab Melia tessellata clinging to a Branch of Coral, and carrying in Each Claw a Living Sea-anemone; B, One of the Claws Further Enlarged to show the Way in which the Anemone is held | 216 |
| 69. | The Common Pea Crab (Pinnotheres pisum), Female. Natural Size | 217 |
| 70. | Cirolana borealis. About Twice Natural Size | 219 |
| 71. | A, Front Part of Body of a Prawn (Spirontocaris polaris), from Above, showing on the Right Side a Swelling of the Carapace caused by the Presence of the Parasite Bopyroides hippolytes in the Gill Chamber; B, the Female Parasite extracted and further enlarged; C, the Male Parasite on Same Scale as the Female | 222 |
| 72. | A Fish-louse (Caligus rapax), Female. × 5 | 225 |
| 73. | Stages of Development of Lernæa branchialis. F is Slightly, the Other Figures greatly, enlarged | 226 |
| 74. | Stages of the Life-history of Hæmocera danæ, One of the Monstrillidæ | 229 |
| 75. | Free-swimming Stages of Sacculina carcini. Much enlarged | 232 |
| 76. | Early Stage of Sacculina within the Body of a Crab | 234 |
| 77. | Rostrum and Fore Part of Carapace, seen from Above, of (A) Red-clawed Crayfish (Astacus fluviatilis) and (B) White-clawed or English Crayfish (Astacus pallipes) | 242 |
| 78. | The Common Shrimp (Crangon vulgaris). Natural Size | 244 |
| 79. | The Norwegian Deep-water Prawn (Pandalus borealis), Female | 246 |
| 80. | The Gribble (Limnoria lignorum). Much enlarged | 254 |
| 81. | Restoration of a Trilobite (Triarthrus becki), showing the Appendages. Upper Side on Right, Under Side on Left. Slightly enlarged | 258 |
| 82. | Ceratiocaris papilio, One of the Fossil Phyllocarida | 262 |
| 83. | Pygocephalus cooperi, from the Coal-measures: Under Side of a Female Specimen, showing the Overlapping Plates of the Brood-pouch | 263 |
| 84. | The Tasmanian "Mountain Shrimp" (Anaspides tasmaniæ), a Living Representative of the Syncarida. Slightly enlarged | 264 |
| 85. | Præanaspides præcursor, One of the Fossil Syncarida, from the Coal-measures of Derbyshire. Slightly enlarged | 265 |
