CONTENTS. 



PAGE 



ON RADIATES IN GENERAL ....... 1 



GENERAL SKETCH OF THE POLYPS ...... 5 



ACTINOIDS .......... 7 



MADREPORIANS ......... 16 



HALCYONOIDS . . . . . . . . . .19 



GENERAL SKETCH OF ACALEPHS ...... 21 



CTENOPHOR^; .......... 26 



EMBRYOLOGY OF CTENOPHOR.E ...... 34 



DISCOPHOR.E .......... 37 



HYDROIDS .......... 49 



MODE OF CATCHING JELLY-FISHES . ... . . .85 



ECHINODERMS ......... 91 



HOLOTHURIANS .......... 95 



ECHINOIDS 101 



STAR-FISHES 108 



OPHIURANS . . . . . . . . . . 115 



CRINOIDS 120 



EMBRYOLOGY OF ECHINODERMS . . . . . . 123 



DISTRIBUTION OF LIFE IN THE OCEAN ..... 141 



SYSTEMATIC TABLE ........ 152 



INDEX 154 



