xxviii LIST OF ILLUSTRATIONS 



PIG. PAGE 



419. Hirudo, cocoon 503 



420. Three Rhynchobdellida . . 506 



421. Proboscis of Clepsine 506 



422. Nephridium of Herpobdella 507 



423. Pontobdella, nephridial system 507 



424. Clepsine, development 508 



425. Diagram of origin of metamerism 511 



426. Diagram illustrating the relationships of the Annulata and 



Trochelminthes 513 



427. Apus cancriformis, dorsal aspect 515 



428. 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 embryo 544 



452. ,, ,, nauplius . . . 545 



453. ,, sections of embryos 546 



454. ,, ,, development of appendages 547 



455. Three Branchiopoda 557 



456. Cladocera 558 



457. Cypris 559 



458. Cyclops and Calocalanus . . . . 560 



459. Various forms of parasitic Eucopepoda 561 



460. Argulus f oliaceus 562 



461. Lepas anatifera 564 



462. Balanus 564 



463. Sacculina carcini 565 



464. Nebalia geoffroyi . . 566 



465. Paranaspides 567 



