Part 2

MADREPORIANS 16

HALCYONOIDS 19

GENERAL SKETCH OF ACALEPHS 21

CTENOPHORÆ 26

EMBRYOLOGY OF CTENOPHORÆ 34

DISCOPHORÆ 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

LIST OF THE WOOD-CUTS.

Unless otherwise specified, the illustrations are drawn from nature by ALEX. AGASSIZ.

FIG. PAGE

1. Transverse section of an Actinia (Agassiz) 5

2, 3, 4. Actinia in different degrees of expansion (Agassiz) 8

5. METRIDIUM MARGINATUM fully expanded 8

6. Vertical section of an Actinia 10

7. View from above of an expanded Actinia 11

8, 9. Young Actiniæ 11

10. RHODACTINIA DAVISII 13