sxvi LIST OF ILIATSTRATIONS 



KIO. >"*»* 



320. Echinus esculentus, peristome . . . 894 



321. Strongylocentrotus . . ■ 395 

 :!22. Corona of Sea-urchin 39t) 

 323. Apical disc of Sea-urchin 397 

 .■'>24. Echinus, lantern of Aristotle . 397 

 .-!2.j. Sea-urchin, anatomy, lateral view . . 398 

 320. 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. ,, tran.sverse section of pinnule . . . 407 



334. ,, sagittal section ... . . 408 



335. Anthenea, venti-al view . 419 



336. Ophioglypha lacertosa . . 420 

 •i.'iT. 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 

 34.0. Diagram to illustrate the relationshijjs i.if the classes of Echino- 



dermata . 433 



346. Nereis dumerilii . 437 



347. ,, ,, parapodium 440 



348. ,, ,, setie . . 441 



349. Nereis diversicolor, proboscis 443 



350. Nereis dumerilii, anatomy 444 



351. ,, ,, transverse section 445 



352. ,, ,, nervous system . 446 



353. ,, ,, eye . . 447 



354. ,, ,, dumerilii, nephridium . 448 



355. ,, ,, development . . 451 



356. „ ,, „ . , 453 



357. Lumbricus herculeus . . 454 

 3.58. ,, setse ... . . . 455 



359. ,, transverse section ... , . 456 



360. ,, herculeus, sagittal section . ... 457 



361. ,, nervous system ... , , . 459 



362. ,, nephridium . . . . 46O 



363. ,, reproductive organs ... , 462 



364. ,, development ... 463 



365. Pulynoe setosissima . . 467 



366. Vermilia ecespitosa . 468 



