LIST OF ILLUSTRATIONS 



FIG. 



414. 

 415. 

 416. 

 417. 

 418. 

 419. 



420. 

 421. 

 422. 

 423. 

 424. 

 425. 

 426. 

 427. 

 428. 

 429. 

 430a 

 430b 

 431. 

 432. 

 433. 

 434. 

 435. 

 436. 

 437. 

 438. 

 439. 

 440. 

 441. 

 442. 

 443. 

 444. 

 445. 

 446. 

 447. 

 448. 

 449. 

 450. 

 451. 

 452. 

 453. 

 454. 

 455. 

 456. 

 457. 

 458. 

 459. 

 460. 



Proboscis of Clepsine 



Nephridium of Herpobdella . 



Pontobdella, nephridial system 



Clepsine, development 



Diagram of origin of metamerism . 



Diagram illustrating the relationships of the Annulata 



Trochelminthes .... 

 Apus cancriformis, dorsal aspect . 

 Lepidurus kirkii, side view . 

 Apus glacialis, ventral aspect 



,, appendages . ... 

 Lepidurus kirkii, sagittal section . 

 Apus, transverse section 

 ,, shell-gland .... 

 ,, cancriformis, nervous system 

 ,, structure of paired eye . 

 ,, development .... 

 .Astacus fiuviatilis, male . 



,, ,, transverse section of abdomen 



,, ,, appendages .... 



,, ,, articulations and muscles of leg 



Section of skin and exoskeleton of Lobster 

 Articulations and muscles of abdomen of Crayfish 

 Astacus fiuviatilis, dissection from right side 



,, „ gills 



,, ,, kidney . . . 



,, ,, transverse section of thorax . 



,, ,, diagram of circulation 



,, ,, nervous sj'stem 



,, ,, reproductive organs 



,, ,, formation of the blastoderm 



,, ,, early embryo . • 



,, ,, nauplius . 



,, ,, section of embryo 



,, ,, advanced embryo 



Three Branchiopoda .... 



,, Cladocera .... 

 Cypris .... 

 Cyclops and Calocalanus 

 Various forms of parasitic Eucopepoda 

 Argulus foliaceus 

 Lepas anatifera . 

 Balanus . . . 

 Sacculina carcini 

 Nebalia geoffroyi 

 Paranaspides 

 Mysis oculata . . . 

 Diastylis 



