Pear slug, 207. Pea weevil, 188. Peck, W. D., on the habits of Stylops and Xenos, 45, 46. Pelopaeus, 207. Pentastoma, 148, 160. Peripatus, 161. Perla, 154. Phora, 40. Phymata, 211. Phytocoris, 211. Pickle worm, 57. Pieris, 55, 197, 207. Pieris brassicae, egg parasite of, 165. Pine plant louse, 220. Pine weevil, 188, 199. Piophila, 83. Pirates, 210. Pissodes strobi, 188. Plan of structure, 186. Plant louse, 220. Platygaster, embryology of, 161. Plum weevil, 194. Podura, 133, 135, 144, 153, 154, 159, 170. Catch of, 139. Spring of, 137. Podurids, the ancestors of the true insects, 157. Poisonous insects, 214. Polynema, embryology of, 164. Poplar tree insects, 92. Potato insects, 63. Prelarval stage of ichneumons, 168. Primitive band, 163, 166. Primitive insects, 175. Prionus, 93. Procris, 60. Protoleptus, 172, 174. Pseudoneuroptera, 178. Ptinus fur, 200. Putnam, F. W., on habits of the bees, 19, 26. Pyrrharctia, 207. Ranatra, 210. Rat-tailed fly, 76. Reduvius, 210. Reproduction, virgin, 168. Respiration of insects, 171. Retardation, theory of evolution by, 167. Rose beetle, 206. Rose saw fly, 196. Rose slug, 207. Rotatoria, ancestors of crustacea, 169. Salpa, 168. Saperda, 91, 208. Sarcoptes, 125. Saw fly, 196, 207. Saw of saw fly, 185. Schioedte on the mouth-parts of the louse, 96. Scolopocryptops, 149. Scorpion, fossil, 158. Scudder on fossil insects of New Brunswick and Illinois, 158. Seira, 143. Selandria, 207. Selandria rosae, 196. September, insects of, 216. Sesia, 194. Seventeen year locust, 212. Sexes, origin of, 152. Sheep tick, 85. Shrimp, 155. Siebold, T. von, on the ears of grasshoppers, xiv. Siebold on parthenogenesis, 168. Silk worm, 51. Silver witches, 128. Simulium, 73. Sitaris, 44. Smith, F., on stingless bees, 18. On parasitic bees, 37. Smynthurus, 142. Species, origin of, 152. Sphinx, 194, 197, 200, 207. Spider, 155. Spider fly, 85. Spindle worm, 215. Spinneret of caterpillars, 183; of spiders, 185. Spring, insects of, 187. Spring of Podura, 185. Spring tail, 127. Squash beetle, 194. Squash bug, 204. Sting of bee, 185. Sting, origin of, 165. Stylops, 21, 45, 152, 179, 188. Sucker of insects, 183. Sugar mite, 124. Swarming of ants, 217. Syllis, 170. Syrphus, 75. Tabanus, 74. Tachina, 39, 189. Tailor bee, 26. Tardigrade, 150, 160. Teleas, embryology of, 166. Templetonia, 143. Tent caterpillar, 187. Tenthredo, 207. Tettigonia, 209. Thanaos, 197. Thecla, 197. Thorax of insects, 173. Thysanura, 127, 154. Ticks, 116. Tinea, 64, 188. Tipula, 194. Tomicus, 199. Tomocerus, 137, 143. Tongue of insects, 183. Torell's discovery of Eophyton in Sweden, 158. Tortrices, 205.