xvi COMPARATIVE ANATOMY 



PAGE 



B. ONTOGENY OF THE HOLOTHURIOIDEA . . . 510 



C. ONTOGENY OF THE ECHINOIDEA .... 519 



D. ONTOGENY OF THE ASTEROIDEA . ... 524 



E. ONTOGENY OF THE OPHIUROIDEA ..... 532 



F. ONTOGENY OF THE CRINOIDEA . . 533 



XXII. PHYLOGENY ... 545 



Review of the most Important Literature ... 551 



CHAPTER IX 



ENTEROPNEUSTA 



I. OUTER ORGANISATION . . . 562 



II. THE BODY EPITHELIUM ..... 563 



III. THE NERVOUS SYSTEM . . 564 



IV. THE SENSORY ORGANS . . . 565 

 V. THE ALIMENTARY CANAL .... . 565 



VI. THE CCELOMIC SACS AND THE BODY MUSCULATURE. . .' 571 



VII. THE "HEART VESICLE" ... 578 



A T III. THE LIMITING MEMBRANES, THE PROBOSCIDAL SKELETON, AND THE 



BRANCHIAL SKELETON ...... 579 



IX. THE BLOOD VASCULAR SYSTEM . . . 581 



X. THE GONADS ........ 585 



XI. ONTOGENY ..... .586 



XII. PHYLOGENY . ...... 591 



Literature ...... . 595 



APPENDAGE TO THE ENTEROPNEUSTA 



I. CEPHALODISCUS . ..... 596 



II. RHABDOPLEURA . .... 600 

 Literature . . . . . . . .602 



INDEX . 603 



