Stages, etc., of Frit Fly (_Oscinis frit_) 183 121. Stages of Horse Bot Fly (_Gastrus equi_) 190 122. Horse Louse (_Hæmatopinus macrocephalus_) 194 123. Common Snake Millipede (_Julus terrestris_) 195 124. A Spider (_Salticus scenicus_) 196 125. Mange Mite of the Pig (_Sarcoptes scabiei, var. suis_) 197 126. Ditto 198 127. The Dog Tick (_Ixodes ricinus_) 203 128. Diagrammatic transverse section through a Thread Worm 210 129. Tail of male _Strongylus armatus_ 213 130. Encapsuled Muscle Trichinæ in flesh 217 131. Male Intestinal Trichina 217 132. Rye Plant in the later stage of the Eelworm Disease 222 133. Ear Cockles of Wheat 225 134. Stages of Beet Eelworm (_Heterodera Schachtii_) 226 135. _Tænia saginata_ 232 136. Common Tapeworm (_Tænia officinalis_) 234 137. Tapeworm Larva (_Tænia solium_) 234 138. Types of Bladder-worm 235 139. Measle of _Tænia solium_ 235 140. Measles in Pork 236 141. Liver Fluke (_Distoma hepaticum_) 241 142. Life History of Liver Fluke 242 143. Diagrams of Molluscs 246 144. Grey Field Slug (_Limax agrestis_) 249 145. Common Starfish (_Asterias rubens_) 252 146. Freshwater Polype (_Hydra_) 254 147. A Jellyfish (_Pelagia noctiluca_) 254 148. A Sea Anemone (_Sagartia nivea_) 254 149. Proteus Animalcule (_Amœba_) 255 ZOOLOGY. INTRODUCTION. I. Subdivision of the Animal Kingdom.