TABLE OF CONTENTS. 



REFERENCES TO THE PRINCIPAL FIGURES. 



For a comparison of the earliest stages of development, see the Segmentation uf the Eijej on 



* Mate I. figs. 1-4, for Comatula. 

 Plate III. figs. 1, 26, Plate IV. figs. 1-7, for the Ophiiiroidea (Amphiura and Opliiothi-ix). 

 Plate V. figs. 6-11, Plate VII. figs. 1-12, for the Asteroidea (Asterina and Asteracantliion). 

 Plate IX. figs. 1, 2, 17-20, Plate X. figs. 1-13, for the Echinoidea (Arbacia, Echinus, and Strongylocentrotus). 

 Plate XIV. fifs. 1-3, Plate XV. figs. 1-3, for the llulothuroidea (Holothuria and Cucuniaria). 



For the Formation of the Blaslula and Oastrula, see 



Plate I. figs. 5, 11, 12, for Comatula. 



Plate III. figs. 3-7, Plate IV. figs. 8-10, for the Ophiuroidea (Amphiura and Ophiothrix). 



Plate V. fics. 12-25, Plate VII. figs. 12-20, for the Asteroidea (Asterina and Asteracanthion). 



Plate IX. fics. 3-12, 19-27, Plate X. figs. 14-24, for the Echinoidea (Arbacia, Echinus, Spatangus, Eohinocar- 



dium, and .Strongylocentrotus). 

 Plate XIII. fig. 12, Plate XIV. figs. 3-.5, Plate XV. figs. 3-6, for the Holotlmroidea (Synapta, Holothuria, 



and Cucumaria). 



For the General Homologies of Eehinoderm Larva, see 

 Plate XV. figs. 14-27. 



For the Development of the different External Parts of the Plutcus or Larva, see 

 Plate I. figs. 8, 9, 21, 27, 28, for Comatula. 



Plate III. figs. 9-14, 29, 30, Plate IV. figs. 11-19, for the Ophiuroidea. 

 Plate V. figs. 1-3, 37-41, 44, 4.5, 47, 48, Plate VI. figs. 4, 12, 14, 16, 18, 24-31, 35-40, 44-46, Plate VII. 



figs. 19-34, for the Asteroidea (Asterina, Echiuaster, and A.steracanthion). 

 Plate IX. figs. 13-16, 30-35, 38-41, Plate X. figs. 26-37, Plate XI. figs. 1-17, 19-24, 28-30, for the Echinoidea 



(Arbacia, Strongylocentrotus, Echinus, Echinocyanuis ? and Echinarachnius ?). 

 Plate XIII. figs. 1-8, 13-16, 18-27, 33-35, Plate XIV. figs. 4, 8, 9, 15-20, Plate XV. figs. 8-11, for the 



Holothuroidea (Synapta, Holothuria, and Cucumaria). 



For the Development of the Water System of the Vasoperitmieal Sacs, see 



Plate I. figs. 12-20, 22-24, for Comatula. 



Plate III. figs. 6-14, Plate IV. figs. 18-20, 27, 29, 31, for the Ophiuroidea (Amphiura and Ophiothrix). 



Plate V. figs. 20-28, 32-34, 36, 38, 43, 46, 49, Plate VI. figs. 2, 3, 6-9, Plate VII. figs. 20-34, Plate VIII. 

 figs. 4-9, 11, 13, 14, 17, 18, for the Asteroidea (Asterina and Asteracanthion). 



Plate IX. figs. 5-13, 19, 21, 26, 27, Plate X. figs. 21-37, for the Echinoidea (Arbacia, Echinus, Spatangus, 

 Echinocardium, and Strongylocentrotus). 



Plate XIII. figs. 4-37, Plate XIV. figs. 5-12, 17, 18, 21-27, Plate XV. figs. 6, 7, 9, for the Holothuroidea (Syn- 

 apta, Holothuria, and Cucumaria). 



For the Development of the Young Eehinoderm, see 

 Plate I. figs. 24, 25, 29-36, Plate II. figs. 1-23, for Comatula. 



Plate III. figs. 14-20, 22-25, 29-33, Plate IV. figs. 20-34, for the Ophiuroulea (Amphiura and Ophiothrix). 

 Plate V. figs. 3, 4, 29-31, 35, 37-41, 45, 47-49, Plate VI. figs. 1, 4, 5, 9, 11, 13, 17, 19, 20-22, 29-32, 37-42, 



47-51, Plate VIII. fig.s. 1-26, for the Asteroidea (Asterin.a, Echinaster, Pteraster, and Asteracanthion). 

 Plate IX. figs. 35-37, 42-45, Plate X. figs. 37, 40-43, Plate XI. figs. 8, 17, 18, 2,5-27, Plate XII. figs. 30-34, 



for the Echinoidea (.Vrbacia, Strongylocentrotus, Echinus, Eehinocyamus ? and Hemiaster). 

 Plate XIII. figs. 6-11, 20-37, Plate XIV. figs. 17-27, Plate XV. figs. 8-11, for the Holothuroidea (Synapta, 



Holothuria, and Cucumaria). 



