xvi 
FIG. 
188, 
189. 
190. 
191. 
192. 
193. 
. 194. 
195. 
196. 
197. 
198. 
199. 
200. 
201. 
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203. 
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206. 
207. 
208, 
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210, 
2m. 
212. 
213. 
214. 
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216, 
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218, 
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220, 
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222, 
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224, 
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226. 
227). 
228, 
229. 
LIST OF ILLUSTRATIONS. 
Mosquito—from Nuttall and Shipley : 
Anurida maritima (after Imms), one of the primitive wing- 
less Collembola s . . . 
Acerentomon, a very primitive. insect . 
Scorpion. f ‘ : . . 
Garden spider 
Dissection of Mygale from the ventral surface—after Cuvier 
Section of lung-book—after Macleod A 
Follicle-mite (greatly enlarged) 
Itch-mite (Sarcoptes scabiez) (greatly “enlarged) 
Tick (Zxodes réduvius, female), dorsal surface (after Wheler), 
showing the oval shield. . 
Tick (Zxodes riduvius, nie ventral surface—after 
Wheler . i ; . 7 
Limulus or King-crab i 5 : 
Young Lzmulus—after Walcott 
Trilobite (Cosocephadétes)—after Barrande . 
Vertical cross-section of a Trilobite (Calymene)—after 
Walcott . 
Sea-spider (Pycnogonum littorale), from the dorsal surface . 
Male of Nymphon—after Sars é P 3 . 
Ideal mollusc—after Ray Lankester . . . 
Stages in molluscan development . 5 . . 
Roman snail (Helix pomatza) i 
Vertical section of the shell of a species of Helix . 
Dissection of snail 
Reproductive organs of Helix pomatia—after Meisenheimer 
Snail (Helix pomatia), laying its eggs—after Meisenheimer 
Diagram of larva of Paludina—after Erlanger 
The fresh-water mussel ( Uzo) f . 
Structure of Axodonta—after Rankin . z 
Development of Anodonta—after Goette 
Side view of Sepza—after Jatta ‘ 
External appearance of a cuttlefish (Lotigo) . 
Diagram of the structure of Sef7a.—Mainly after Pelseneer | 
Diagram of circulatory and excretory systems in a i as 
like Sepia—after Pelseneer 
Male of Avgonauta (after Jatta), showing ‘« hectocotylus ” 
arm ; compare Fig. 9 of female . 
Bunch of Sepia eggs attached to plant—after Lieto 3 
Common buckie (Buccinum undatum) ‘ 
Bivalve (Panopea norvegica), showing siphons 
Nudibranch (Dendronotus arborescens), showing dorsal out- 
growths forming adaptive gills . 
Ventral surface of Patella vulgata—after Forbes and Hanley 
Chiton—after Prétre : 
Dorsal view of nervous system of Chiton—after Pelseneer . 
Anatomy of Chiton . 
A Pteropod (Cymbulia peronii), showing the wing- ‘like ex- 
pansions (pteropodial lobes) of the mid-foot . s 
