( iii ) 
TABLE OF CONTEXTS. 
PAGK 
Table of Contents ......... iii 
List of Plates .......... vi 
List of Illustrations in Text ........ vi 
Preface ........... ix 
Geological Time-scale . . . . . . Opposite p. 1 
Plan and Principles of Arrangement ..... 1 
Gallery XI. Sthatigraphicai, Series 4 
Historical Collections ..... 6 
Dynamical Series ...... 12 
Tracks and Markings ...... 14 
Gallery X. PROTOZOA 14 
Class Foraminifera 16 
Eozoon 25 
Class Radiolaria ...... 26 
PORIPER.4. (Sponges) ...... 29 
Class Calcarea ...... 31 
Class Hexactinellida ..... 32 
Class Demospongiae ..... .35 
Class (?) OCTACTINELLIDA ..... 38 
Class (?) Heteractinellida . . . .39 
Archaeocyathinae ..... 42 
COELENTERA 43 
Class ScYPiiozoA -44 
Class Hydrozoa ...... 45 
Class Anthozoa ...... 48 
Gallery VIII. ECHINODERIMA 58 
Class Crinoidea ...... 58 
Class Cystidea ...... 63 
Class Blastoidea ...... 66 
Class Edrioasteroiuea ..... 67 
Class Asteroidea ...... 68 
Class Ophiuroidea 70 
Class Echinoidea ...... 71 
Class Holothurioidea ..... 76 
Echinoderms as Rock-formers ... 76 
