Xll 



CONTENTS. 



SECTION V. THE CLASS OF TTJNICATA OR ASCIDIANB. . 429 

 SECTION VI. THE CLASS OP BRACHIOPODA on BRACHIO- 



PODS 433 



SECTION VII. THE CLASS OF POLYZOA OR BRYOZOANS. ... 435 



CHAPTER V. 

 THE RADIATA OR RADIATES 440 



SECTION I. THE RADLVTA CONSIDERED AS A BRANCH. . . . 440 

 SECTION II. THE CLASS OF ECHINODERMATA OR ECHINO- 



DERMS 441 



Sub-Section I. The Ecliinodermata Considered as a Class. 441 

 II. The Order of Holothurioidea or Holothu- 



rians 442 



III. The Order of Echinoids or Sea-Urchins. . 445 



IV. The Order of Asteroidea or Star-Fishes. . . 449 

 V. The Order of Ophiurioidea or Serpent- 

 Stars 451 



VI. The Order of Crinoidea or Crinoids 453 



SECTION III. THE CLASS OF ACALEPH.E OR JELLY-FISHES. 456 



Sub-Section I. The Acalephs Considered as a Class 456 



II. The Order of Ctenophorae or Beroid Me- 

 dusae 458 



III. The Order of Discophorse or Meduste pro- 



per 459 



IV. The Order of Hydroidea or Hydroids. . 461 

 SECTION IV. THE CLASS OF POLYP! OR POLYPS 466 



Sub-Section I. The Polypi Considered as a Class 466 



II. The Order of Alcyonaria or Sea-Pens, Sea- 

 Fans, etc 473 



III. The Order of Actinaria or Sea-Anemones. 476 



IV. The Order of Madreporaria or Madre- 



pores, Astraeans, etc 478 



CHAPTER VI. 



THE PROTOZOA OR PROTOZOANS 435 



SECTION I. THE PROTOZOA CONSIDERED AS A BRANCH. 485 



SECTION II. THE SPONGIDA OR SPONGES 488 



SECTION III. THE INFUSORIA OR CILIATA 490 



SECTION IV. THE FLAGELLATA 491 



SECTION V. THE RHIZOPODA 492 



SECTION VI. THE GREGARINIDA 495 



SECTION VII. THE MONERA 495 



CHAPTER VII. 

 CO^CLUDHSTG REMARKS 496 



