PLATE VIII. 



Fig. 1. BOTRTLLUS 454 



Fig. 2. AMAROUCIUM. a. A single individual removed 



from its cell and magnified 455 



Fig. 3. PYKOSOMA 459 



Fig. 4. ASCIDIA 445 



Fig. 5. ASCIDIA INTESTINALIS 452 



Fig. 6. SALP^:. a. Solitary individual, b. A chain 

 of aggregated SalpaB. c. Chain of embryo 



Salp derived from a 461 



Fig. 7. PHOLAS DACTTLTJS 486 



Fig. 8. SOLEN SILIQT7A 480 



Fig. 9. PECTEN 466 



Fig. 10. APLTSIA 497 



Fig. 11. BuccnnrM 500 



Fig. 12. PURPURA 500 



Fig. 13. CHITON 505 



Fig. 14. EOLIS 509 



Fig. 15. DORIS 506 



Fig. 16. EGOS OF CUTTLE-FISH 504 



Fig. 17. AMPHIOXUS , . . . , 514 



Fig. 18. ECHENEIS EEMOEA .., r 514 



Fig. 19. SYNGNATHTJS , . , 519 



Fig. 20. STNGNATHUS HIPPOCAMPUS 519 



