XIV CONTENTS. 



CHAPTER XXIII. 



General characters of the Echinoidea — Structure of the test and its 

 appendages — Classification of the Echinoids — Distribution of 

 the Echinoids in time — Characters and distribution of the Pale- 

 chinoids — Cystocidaridae — Bothriocidaridae — Perischoechinidae 

 — Characters and distribution of the Euechinoids — Regular 

 Euechinoids — Cidaridae — Salenidae — Echinothuridae — Glypho- 

 stomata — Irregular Euechinoids — Conoclypeidae — Clypeastridae 

 Echinoconidae — Cassidulidae — Holasteridae — Spatangidae, 366-390 



CHAPTER XXIV. 



General characters of the Asteroidea — Integumentary skeleton of the 

 Star-fishes — Ambulacral system and skeleton — Distribution of 

 Asteroids in space and time — Classification — The Encrinas- 

 teriae and their chief types — The Asteriae verse — General char- 

 acters of the Ophiuroidea— Integumentary skeleton of Ophi- 

 uroids — Ambulacral system — Reproductive system — Distribu- 

 tion of Ophiuroids in space and time — The Euryalida — The 

 Ophiurida — The Protophiurida — General characters of the 

 Holothuroidea — Remains of fossil Holothurians, . . 391-407 



CHAPTER XXV. 



General characters of the Pelmatozoa — General characters of the 

 Crinoidea — Structure of Antedon — Development of Antedon — 

 General morphology of the Stalked Crinoids — Classification of 

 the Crinoids — Distribution of the Crinoids in space and in time — 

 Characters of the Palaeocrinoidea — Actinocrinidae — Barrandeo- 

 crinidae — Platycrinidas — Rhodocrinidae — Calyptocrinidas — Ich- 

 thyocrinidae — Crotalocrinidas — Haplocrinidae — Symbathocrinidas 

 — Cupressocrinidae — Gasterocomidce — Hybocrinidae — Hetero- 

 crinidae — Anomalocrinidae — Belemnocrinidae — Cyathocrinidae — 

 Poteriocrinidae — Astylocrinidae — Catillocrinidas — Calceocrinidas 

 — Characters of the Neocrinoidea — Encrinidae — Eugeniacrinidas 

 — Holopidae — Hyocrinidae — Plicatocrinidae — Apiocrinidae — 

 Bourgueticrinidae — Pentacrinidas — Marsupitidae — Comatulidse — 

 Saccocomidae, 408-446 



CHAPTER XXVI. 



General characters of the Cystoidea — Morphology of Cystoids — Dis- 

 tribution of the Cystideans in time — Classification of Cystideans 

 — Suborders and principal genera of the Cystideans — General 



