XVI LIST OF ILLUSTRATIONS. 



FIG. 



185. Life histories of insects ..... 



1 86. Life history of the silk -moth (Bombyx mart) 



187. Development of blow-fly (Calliphora erythrocephala) after 



Thomson Lowne ..... 



1 88. Mosquito -from Nuttall and Shipley 



189. Amirida maritima (after Imms), one of the primitive wing- 



less Collembola ...... 



190. Acerentojuon^ a very primitive insect 



191. Scorpion, ventral surface 



191 A. Scorpion, dorsal surface .... Facing 



192. Garden spider . . . . . 



193. Dissection of Mygak from the ventral surface after 



Cuvier ....... 



194. Section of lung-book after Macleod 



195. Follicle-mite (greatly enlarged) 



196. Itch-mite (Sarcoptes scabiei] (greatly enlarged) 



197. Tick (Ixodes ridiivius, female), dorsal surface (after \Yheler), 



showing the oval shield .... 



198. Tick (Ixodes riduvius, female), ventral surface after 



Wheler ....... 



igSA. Mouth-parts of a tick .... Facing 



199. Limulus or King-crab, ventral aspect 



I99A. Limulus or King-crab, dorsal aspect . . Facing 



200. Young Limulus after Walcott 



201. Trilobite (Conocephalites} after Barrande . 



202. Vertical cross-section of a Trilobite (Caly/uenc] after 



Walcott .... 



203. Sea-spider (Pycnogonum littoral e\ from the dorsal surface . 



204. Male of Nymphon after Sars .... 



205. Ideal mollusc after Ray Lankester 



206. Stages in molluscan development 



207. Roman snail (Helix pomatia] .... 



208. Vertical- section of the shell of a species of Helix 



209. Dissection of snail ...... 



210. Reproductive organs of Helix pomatia after Meisenheimer 



211. Snail (Helix pomatia}) laying its eggs after Meisenheimer 



212. Diagram of larva of Paludina after Erlanger 



213. The fresh-water mussel ( Unto] 



214. Structure of Anodonta after Rankin 



215. Development of Anodonta after Goette . . 



216. Side view of Sepia after Jatta .... 



217. External appearance of a cuttlefish (Loligo] . 



218. Diagram of the structure of Sepia mainly alter Pelseneer . 



219. Diagram of circulatory and excretory systems in a Decapod- 



like Sepia after Pelseneer .... 



220. Male of Argonauta (after Jatta), showing " hectocotylus " 



arm ; compare Fig. 9 of female 



221. Bunch of Sepia eggs attached to plant after Jatta . 



222. Common buckie (Buccinum undatum] . . 



223. Bivalve (Panopcea norvegica}> showing siphons . 



