LIST OF ILLUSTRATIONS XXI 



FIG. 



263. Bunch of Sepia eggs attached to plant — after Jatta 



264. Common buckie {Buccinum undatum) . 



265. Bivalve {Panopcea norvegica), showing siphons 



266. Nudibranch {Dendronotus arbor escens), showing dorsal out 



growths forming adaptive gills ... 



267. Ventral surface of Patella vulgata — after Forbes and Hanley 



268. Chiton — after Pretre ..... 



269. Dorsal view of nervous system of Acanthochiton — after 



Pelseneer ....•• 



270. Anatomy of Chiton ..... 



271. A Pteropod [Cymhulia peronii), showing the wing-like ex 



pansions (pteropodial lobes) of the mid-foot 



272. Stages in moUuscan development 



273. Proneomenia. Nervous system — from Hubrecht 



274. Section of shell of Nautilus — after Lendenfeld 



275. The Pearly Nautilus {Nautilus pompilius) — after Owen 



276. Section of the shell of Spirula .... 



277. Spirula, a small Decapod cuttlefish 



278. Male of Balanoglossus {Dolichoglossus) kowalevskii — after 



Bateson ...... 



279. Dissection of Balanoglossus .... 



280. Transverse section through gill-slit region of Ptychodera 



minuta — after Spengel .... 



281. Direct development of Dolichoglossus — after Bateson 



282. Tomaria larva, from the side — after Spengel . 



283. Piece of a colony of Cephalo discus, showing the tubes in 



habited by the animals — after Ridewood 



284. An individual Cephalodiscus — after Ridewood 



285. Dissection of Ascidian — after Herdman 



286. Diagram of Ascidian — after Herdman 



287. Young embryo of Ascidian (Clavelina) — after Van Beneden 



and Julin ...... 



288. Embryo of Clavelina — modified after SeeUger 



289. Part of a colony of Botryllus, showing two individuals em 



bedded in a gelatinous matrix and with a common 

 exhalant aperture . . .^ . 



290. Asexual reproduction in Salpa .... 



291. " Nurse " of Doliolum mUlleri — after Uljanin. 



292. Sexual individual of Doliolum millleri — after Uljanin 



293. Diagram of Salpa africana .... 



294. Structure of Appendicular ia — after Herdman 



295. Lateral view of Amphioxus — after Ray Lankester . 



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