xxvi LIST OF ILLUSTRATIONS 



FIG. PAGE 



320. Echinus esculentus, peristome 394 



321. Strongylocentrotus 395 



322. Corona of Sea-urchin 396 



323. Apical disc of Sea-urchin 397 



324. Echinus, lantern of Aristotle 397 



325. Sea-urchin, anatomy, lateral view 398 



326. Echinoid, transverse section of ambulacral zone . " . . . 399 



327. Sea-urchin, anatomy, oral view . 400 



328. Cucumaria planci . 401 



329. Anatomy of a Holothurian 403 



330. Antedon 405 



331. Aboral view of Antedon 406 



332. Antedon disc . . .406 



333. ,, transverse section of pinnule 407 



334. ,, sagittal section 408 



335. Anthenea, ventral view 419 



336. Ophioglypha lacertosa 420 



337. Astrophyton arborescens . 421 



338. Diagram of spine of Sea-urchin 422 



339. Pedicellaria of Arbacia punctulata 422 



340. Hemipneustes radiatus 423 



341. Clypeaster sub-depressus 423 



342. Metacrinus interruptus 424 



343. Development of Echinoderms 431 



344. ,, ,, Antedon 432 



345. Stalked larva of Antedon . 433 



346. Diagram to illustrate the relationships of the classes of Echino- 



dermata 437 



347. Nereis dumerilii 440 



348a. ,, ,, parapodium -. 441 



348b. ,, ,, setae 441 



349. Nereis diversicolor, proboscis 443 



350. Nereis dumerilii, anatomy 444 



351. ,, ,, transverse section 445 



352. ,, ,, nervous system 446 



353. „ ,, eye 447 



354. ,, ,, nephridium . . . . . . . 448 



355. ,, ,, development . . 451 



356. „ ,, ,, . - 453 



357. Lumbricus herculeus 454 



358. ,, setae ; 455 



359. ,, transverse section 456 



360. ,, sagittal section 457 



361. ,, nervous system 459 



362. ,, nephridium 460 



363. ,, reproductive organs 462 



364. ,, development . . .. . . . . i . 463 



365. Polynoe setosissima 467 



