LIST OF ILLUSTRATIONS. 



r.v;K 

 Bacillus rossii . . . . . 1 o I 



The Eggs and immature and Adult Forms of 



1'hyllium siccifolium . . To face page 132 

 Cockroaches . . .133 

 Common Earwigs ....... 135 



Different Forms of White Ants . . . .137 



A Female Termes 138 



Caecilius fenestratus 140 



Ferla marginata and its Pupa 141 



Ephemera vulgata . 142 



Larva and Pupa of Ephemera vulgota . . .113 



Libellula depressa 144 



Agrion puella Nymph of Libellula, and the Per- 

 fect Insect Emerging 145 



The Larva and Imago of Thrips cerealiura . . 146 

 Philopterus selcifrons . . . . . .147 



Lepisma saccharins ...... 148 



Orchesella cincta 149 



Parts of Mouth of a Scolopendra . . . .150 

 The Development of Julus terrestris . . . 152 



Scolopendra cingulata 153 



Scutigera forceps 154 



Julus terrestris 156 



Panropoa Huxleyi Peripatus capensis . . . 157 

 Under Surface of Scorpio occitanus. . . . 160 

 Androctonus (or Scorpio) occitanus. . . .161 

 Phrynus reniforinis Chelifer cancroides . .163 



Galeodes araneoides 165 



Lycosa andrenivora . . . . . .167 



Cteniza fodiens and its Nest . . To face page 170 



Salticus scenicus 171 



Dolomedes mirabilis 172 



Thomisus citretis Drassus cupreus . . .173 



Argyroneta aquatica 174 



Theridion nervosum . . . . . .175 



The Common Garden Spider . . . . .177 



Gasteracantha arcuata . . . . . .179 



Trombidium holoseiiceum The Metamorphoses of 



Hydrachna globulus . . . . .182 



Gamasus coleoptratorum 183 



Ixodes flavomaculatus . . . . . .184 



Tyroglyphus domesticus Demodex folliculorum . 185 

 Macrobiotus hufelandi Pentastoma toenioides . 18G 

 Ammothoa pycnogonoides Larva of Nymphon . 187 

 Diagram of the Body Segments of a Lobster . . 190 

 Appendages of the Head and Thorax of a Lobster . 191 

 The Third Ring of the Abdomen of the Lobster 



Side View of Common Crab . . . .192 



A few of the Eggs of the Common Crab Diagram- 

 matic Section of a Lobster's Body Gastric 

 Teeth of Lobster and Crab . . . .193 



Three Stages in the Metamorphoses of the Common 



Shore Crab 194 



Metamorphoses of a Prawn of the Genus Penaeus . 195 

 Nerves of Maia squinado Nerves of Amphipod, 



Isopod, and Lobster 197 



The Slender-beaked Spider Crab . . . .198 



Maia squinado . . . . . . .199 



The Common Shore Crab Henslow's Swimming 



Crab 200 



The Masked Crab 201 



Violet Land Crab of Jamaica Pinnotheres pisum . 202 

 A Group of Hermit Crabs . . To face page 203 



Birgus latro 203 



Hermit Crab in Shell 204 



The Spiny Lobster . . . . To face page 205 

 Larva of Palinurus vulgaris The Common Lobster 205 

 Young Lobsters The Norway Lobster . . . 206 

 Structure of Eye of Lobster Eye of Trilobite . 207 

 The Common Brown Shrimp The Common Prawn 208 



Squilla mantis 209 



Opossum Shrimp A Gigantic Isopod . . .210 

 Tanais Parasitic Isopods : Bopyrus, Phryxus, 



Cryptothyria 211 



An Amphipod ... .... 212 



The Spectre, or Skeleton Shrimp- -The Horseshoe 



Crab The King Crab 213 



Phyllopoda 215 



Forms of Cladocera, Ostracoda, and Copepoda . '217 

 Ciiripedia . . . . . . . .219 



Larval Forms of Cirripedia 220 



The Earth Worm 225 



Spine and Spinet of Lumbricus terrestris . . 226 

 Northia tubicola Foot of Nephthys . . . 228 

 The Sea Mouse . . . - . .230 



The Nervous System of Nereis . . . .231 

 The Lurg Phyllodoce kinbergii .... 232 



Lug Worm ." 233 



Transverse Section of Lug Worm Arenia fiagilis 234 

 Eunice and Cirratulus . . . To face page 235 



Trophonia plumosa 235 



Terebella emmalina 236 



Orthonia fabrici Nervous System of Serpula con- 



tortuplicata ....... 238 



Serpula vermicularis . . . . . .239 



The Medicinal Leech . . . . . .241 



Intestinal Tube of Sanguisuga ; Nervous System of 



Malacobdella grossa 242 



Larva of Gephyrea Sipunculus Bernhardus . . 244 

 Larva of Phascolosoma and of Sipunculus Rotifer 



vulgaris 245 



Monolabis gracilis Brachionus amphiceros . . 247 

 Jaws of Brachionus brevissimus Polyarthra pla- 



typter . . . . . . . 248 



Floscularia trifolium 249 



Echinorhynchus angusta ; Echinorhynchus nodu- 



lata . . 250 



Intestinal Canal of a Nematoid Trichina spiralis . 251 



Filaria Bancroftii 252 



The Thread Worm Strongylus pergracilis . .253 



Head of Echinococcus 255 



The Tape Worm . ..... 256 



Development of Liver Fluke Digestive Apparatus 



of Eurylepta sanguinolenta .... 257 



Astropecten irregularis . . . . . .259 



Pluteus Larva of the Purple Egg-Urchin Pluteus 



paradoxus, the Advanced Larva of an Ophiurid 262 

 Side View of the Advanced Brachiolaria Larva of a 



Starfish Larva of Holothuria tubulosa . . 263 

 Diagram of a Side View of Holothurian Larva 

 represented in preceding Fig. Dorsal View of 

 the Larva of the Rosy Feather-star . . . 264 

 Pentacrinoid Larva of the Rosy Feather-star . . 265 

 Diagrammatic Representation of a Cross-section of 

 an Arm of the Common Cross-fish Diagram 

 of the Blood- vascular System of a Starfish . 266 



The Common Brittle-star 267 



Diagram on a Longitudinal Section through the 



Disc and an Arm-base of an Ophiurid . . 268 

 Diagram on a Cross-section of an Ophiurid arm . 269 

 A General View of the Test of an Urchin Internal 

 View of the Test of Echinus microstoma ; the 



Dental Pyramid 270 



View of the Interior of the Bisected Test of the 



Purple Egg-Urchin 271 



A Holothurian with its Buccal Tentacles Expanded 272 

 A Stalked Crinoid or Sea-Lily . . . .273 

 The Rosy Feather-star Longitudinal Section 



through the Body of an Irregular Feather-star 274 

 Cross-section of a Pinnule of the Arctic Feather- 

 star Diagram Showing the Course of the 

 Axial Cords proceeding from the Chambered 

 Organ within the Calyx of a Feather-star . 275 

 Beroe pileus . . . . . . . 278 



Venus' Girdle 279 



Jelly-fishes To face page 281 



Aurelia aurita Strobila of Aurelia flavidula . .281 

 Reproduction of Discophora Lucernariaj on Piece 



of Seaweed 282 



Physalia utriculus 283 



