CONTENTS. 



CHAPTER XVI. 



Ctenophora General characters Anatomy of Pleurobrachia Divi- 

 sions of Ctenophora, ....... 142-146 



CHAPTER XVII. 



Distribution of Actinozoa in space Coral Reefs, their structure, and 

 mode of origin Distribution of Actinozoa in time Tabular view 

 of the divisions of the Zoantharia Sclerodermata and Rugosa, 147-153 



CHAPTER XVIII. 



Annuloida General characters of the Annuloida General characters 



of the Echinodermata Development of the Echinodermata 



Divisions of Echinodermata, ...... 154-157 



CHAPTER XIX. 



Echinoidea General characters Anatomy of Echinus Divisions of 

 Echinoidea, 157-163 



CHAPTER*XX. 



Asteroidea and Ophiuroidea General characters of the Asteroidea 

 Divisions of the Asteroidea General characters of the Ophiuroi- 

 dea Families of the Ophiuroidea, 164-170 



CHAPTER XXI. 



Crinoidea, Cystoidea, and Blastoidea General characters of Crinoi- 



dea Of Cystoidea Of Blastoidea, 170-177 



CHAPTER XXII. 



Holothuroidea General characters Families of Holothuroidea, 177-180 



CHAPTER XXIII. 



Distribution of Echinodermata in space Distribution of Echinoder- 

 mata in time Crinoidea Blastoidea Cystoidea Asteroidea 

 Ophiuroidea Echinoidea Holothuroidea, . . . 180-183 



CHAPTER XXIV. 



Scolecida General characters of the class Scolecida Entozoa 

 Platyelmia Tseniada Structure and development of the Tape- 

 worm Hydatids, 183-189 



CHAPTER XXV. 



Trematoda and Turbellaria General characters of the Trematoda 

 General characters of the Turbellaria Planarida Nemer- 

 tida, 189-193 



