XXVI 



LIST OF WOOD-CUT ILLUSTRATIONS. 



255. Section of Faujasina, after Williamson 



256. Internal cast of Polystomella . 



257. Vertical Section of Nummulina 



258. Portion of ditto more highly magnified 



259. Horizontal Section of Nummulina 



260. Internal cast of Nummulina . 



261. Heterostegina 



262. Section of Orbitoides Fortisii parallel to its surface 



263. Portions of ditto, more highly magnified 



264. Vertical Section of Orbitoides Fortisii . 



265. Internal cast of Orbitoides Fortisii 



266. Haliomma Humboldtii, after Ebrenberg 



267. Perichlamydium pratextum, Ditto 



268. Stylodyctya gracilis, Ditto . 



269. Astromma Aristotelis, Ditto 



270. Polycystina, from Barbadoes, Ditto 



271. Structure of Grantia, after Dobie 



272. Portion of Halichondria 



273. Siliceous spicules of Pachymatisma 



274. Hydra fusca, after Milne-Edwards 



275. Ditto, in gemmation, after Trembley 



276. Medusa-buds of Syncoryna, after Sars . 



277. Sertularia cupressina, after Johnston . 



278. Thaumantias pilosella, after E. Forbes . 



279. Development of Medusa-buds, after Dalyell 



280. Development of Medusce Ditto 



281. Cydippe and Beroe, after Milne -Edwards 

 2S2. Noctiluca miliaris, after Quatrefages . 



283. Spicules of Alcyonium and Gorgonia 



284. Spicules of Gorgonia guttata and Muricea elongata 



285. Filiferous capsules of Actinia, &c, after Gosse 



286. Section of Shell of Echinus .... 



287. Calcareous reticulation of Spine of Echinus 



288. Ambulacral disk of Echinus . 



289. Transverse Section of Spine of Acrocladia . 



290. Spines of Spatangus 



291. Structure of Tooth of Echinus, after Salter 



292. Calcareous skeleton of Astrophyton 



293. Calcareous Skeleton of Holothuria 



294. Ditto of Synapta . 



295. Ditto of Chirodota . 



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



297. Pluteus-larva of Echinus, after Miiller . 



298. Antedon rosaceus (Comatula rosacea) 



299. Pentacrinus-larva of Antedon, after Thompson 



300. Cells of Lepralia, after Johnston . 



301. Bird's-head processes of Cellularia and Bugula, after 



and Busk 



302. Amaroucium proliferum, after Milne-Edwards 



303. Botryllus violaceus, Ditto 



304. Perophora, after Lister 



305. Transverse Section of shell of Pinna . 

 3 06. Membranous basis of ditto .... 

 307. Vertical Section of ditto .... 



Johnston 



