LIST OF ILLUSTRATIONS. 



XXI 



230. Spicules of ^Zfj/OTOMTO and (jorg'OKin, . 



231. Ditto of Gorgonia guttata, 



232. Spicules of JlfMrJceaetojig'ata, 



233. FiliferouB capsules of Actinia, &c., after Gosse, 



234. Section of Shell of Echinus, 



235. Calcareous reticulation of Spine of Echinus, 



236. Ambulacral disk of ^cAiKMS, 



237. Transverse Section of Spine otAcrocladia, . 



238. Spines of Spatangus, 



239. Calcareous skeleton of Astrophyton, 



240. Ditto of Holothuria, 



241. Ditto of Synapia, 



242. Ditto ■ of Ohirodoia, 



243. Bipinnarian larva of Star-fish, after Miiller, 



244. Pluteus-larva of Echinus, after Miiller, . 



245. Cells of Lepralice, after Johnston, . 



246. Laguncula repens, after Van Beneden, . 



247. Bird's-head processes of Cellularia and Bugula, after Johnston and Busk, 



248. Amarouciiim proliferum, after Milne-Edwards. 



249. Botryllus violaceus, Ditto 



250. Perophora, after Lister, . 



251. Transverse Section of Pt'jina, 



252. Membranous basis of Ditto 



253. Vertical Section of Ditto 



254. Oblique Section of Ditto 



255. Section of hinge-tooth of Mya, 



256. Nacre of ^uicjiZa, 



257. Tubular shell-structure of Anomia, . 



258. Vertical Section of shell of Unio, 



259. Internal surface of shell of rereSrafafa, 



260. External Ditto Ditto 



261. Vertical Sections of Ditto . 



262. Horizontal Section of shell of Terebratula bullata, 



263. Ditto Ditto oi Megerlia lima, 



264. Ditto Ditto of Spiriferina rostrata, 



265. V&iaXe oi Helix hortensis, .... 



266. Ditto o! Zonites cellarius, 



267. Ditto of Trochus zizyphinus, 



268. Ditto of Doris tuberculata, 



269. Ditto of Buccinum, under polarized light, . 



270. Embryoes of Nudibranchs, after Alder and Hancock, 



271. Embryonic development of Parpttra, 



272. Latter stages of the same, 



273. Structure of PoZyceZi>, after Quatrefages, 



274. Circulation of Terebella, after Milne-Edwards, . 



275. Ammothea pycnogonoides, after Quatrefages, 



276. Cyclops qiiadricornis, after Baird, 

 2li. Development of Balanus, after Bate, 



278. Metamorphoses of Carcinus, after Couch, 



279. Scale of Morpho Mendaus, .... 



280. Battledoor scale of Polyommatus argus, after Quekett, 



281. ?>c&\6s of Podura plumbea, .... 



282. Hairs of Myriapod and Bermesies, 



283. Head and eyes of Bee, .... 



284. Section of Eye of Melolontha, after Strauss-Durckheim, 



285. Antenna of Cockchafer, .... 



286. Portions of ditto more highly magnified, 



287. Tongue of P?!/, ' . 



288. Tongue, &c., of Honey Bee, 



289. Proboscis of Vanessa, .... 



290. Tracheal system of Nepa, after Milne-Edwards, 



