xxviii LIST OF ILLUSTRATIONS 



FIG. PAGE 



419. Hirudo, cocoon 503 



420. Three Rhynchobdellida 506 



421. Proboscis of Clepsine . . . ... 506 



422. Nephridium of Herpobdella 507 



423. Pontobdella, ncphridial system ... .... 507 



424. Clepsine, development 508 



42."). Diagram of origin of metamerism 511 



I -;. Diagram illustrating the relationships of the Annulata and 



Trochehninthes . . . . . . . .513 



427. Apus cancriformis, dorsal aspect . . . . . . . .515 



4i'8. Lepidurus kirkii, side view . 516 



429. Apus glacialis, ventral aspect 517 



430. ,, appendages 518 



431. Lepidurus kirkii, sagittal section 520 



432. Apus, transverse section 521 



433. shell-gland . . 522 



434. ,, cancriformis, nervous system 523 



435. ,, structure of paired eye 524 



436. ,, development 525 



437. Astacus fluviatilis, male 527 



438. ,, transverse section of abdomen . . . .527 



439. ,, ,, appendages 529 



440. ,, ,, articulations and muscles of leg .... 532 



441. Section of skin and exoskeleton of Lobster . . . 533 



442. Articulations and muscles of abdomen of Crayfish . . . 534 



443. Astacus fluviatilis, dissection from right side 535 



444. ,, gills . . ... . 536 



445. kidney .538 



446. ,, ,, transverse section of thorax ..... 539 



447. ,. ,, diagram of circulation .... . .540 



448. ,, ,, nervous system .... .541 



449. ,. ,, reproductive organs .... . 543 



450. ,, ,, formation of the blastoderm . 544 



451. ,, ,, ventral view of embi \ <> . . . 544 



452. ,, ,, nauplius ....... . 545 



453. ., ,, sections of embryos .... . 546 



454. ,, development of appendages ... . 547 



455. Three Branchiopoda . 557 



t.'.ti. ,, CludoccTu 558 



457. Cypris ... .559 



458. Cyclops and Calocalanus . . 500 



459. Various forms of parasitic Eucopepoda . 561 



460. Argulus foliaceus .... . 561' 



461. Lepas anatifera. . . . ,-,(14 



462. Balanus . . . 564 



463. Sacculina carcini . . . 505 



464. Nebalia geoffroyi . ;,i;t; 



465. Paranaspides .... .-,d7 



