LIST OP ILLUSTRATIONS xxvii 



FIO. PAGE 



371. Polynoe setosissima 457 



372. Galeolaria coespitosa 457 



373. Chaetopterus 458 



374. Setae of various Polychaeta 458 



375. Section of setigerous sac of an Oligochsete 458 



376. Polynoe extenuata, anterior end 459 



377. Polychaeta, various, heads 460 



378. Tu ifex 461 



379. Terebella 462 



380. Aphrodite, enteric canal 464 



381. Saccocirrus, transverse section 466 



382. Phyllodoce, nephridium 468 



383. Nephridia and coelomoducts 469 



384. Diagram illustrating development of gonad of Polychseta . . 470 



385. Pionosyllis elegans 472 



386. Spirorbis Isevis 473 



387. Eupomatus, development of trochophore 474 



388. Autolytus cornutus, budding . . . . . . . 475 



389. Syllis ramosa 476 



390. Serpulse with their tube* 476 



391. Myzostoma 478 



392. anatomy 479 



393. Echiurus 480 



394. anatomy . 481 



395. ,, nervous system 481 



396. Bonellia viridis, female 482 



397. Bonellia, anatomy 482 



398. Echiurus, ciliated funnel 482 



399. Bonellia, male 483 



400. Echiurus, trochophore 483 



401. Sipunculus nudus, anterior extremity 485 



402. tentacular fold .485 



403. ,, anatomy 486 



404. ,, ,, nervous system 486 



405. Priapulus 490 



406. Polygordius neapolitanus . . 491 



407. Protodrilus 492 



408. Polygordius neapolitanus, transverse section 492 



409. ,, ,, trochophore 493 



410. later stage . . . .493 



411. Hirudo medicinalis 495 



412. ,, transverse section 496 



413. ,, jaw 497 



414. ,, australis, dissection from dorsal aspect 498 



415. australis leftside 499 



416. ,, medicinalis, nephridium 500 



417. ,, diagram of blood -channels 501 



418. section of eye 502 



