List of Illustrations 



PLATES 



FACING PAGE 



I. Starfishes and Ophiuran, Asterias forbe.si, Henrida 



sanguinolenta, and Ophiura brevispina . . . 13 



II. Skeleton of Starfish, Asterias forbesi ... 19 



III. Aboral surface of Starfish, Asterias forbesi . . 21 



IV. Oral surface of Starfish, Asterias forbesi . . 22 

 V. Anatomy of Starfish, Asterias vulgar is . . . 25 



VI. Rate of growth of Starfish, Asterias forbesi . . 41 



VII. Variation, Asterias forbesi 43 



VIII. Asterias forbesi. and Asterias vulgar is ... 60 



IX. Asterias vulgar is 61 



X. Asterias tenera 63 



XI. Henrida sanguinolenta 65 



XII. Variation, Ophiopholis aculeata 67 



XIII. Skeleton of Ophiuran, Ophiopholis aculeata . . 68 



XIV. Skeleton of Ophiuran, Ophiura brevispina . . 71 

 XV. Ophiura brevispina 79 



XVI. Ophiopholis aculeata 80 



XVII. Amphipholis squamata 81 



XVIII. Amphioplus abditus ....... 82 



XIX. Amphioplus abditus and Amphioplus madlentus . 84 



XX. Sea-urchin, Arbada punctulata 85 



XXI. Skeleton of Sea-urchin, Strongylocentrotus dro- 



bachiensis 87 



XXII. Anatomy of Sea-urchin, Arbada punctulata , . 89 



XXIII. Skeleton of Disk-urchin, Echinarachnius parma . 92 



XXIV. Anatomy of Disk-urchins, Mellita pentapora and 



Echinarachnius parma ...... 95 



XXV. Arbada punctulata . . . . . . . 107 



XXVI. Strongylocentrotus drobachiensis ..... 108 



XXVII. Echinarachnius parma no 



XXVIII. Mellita pentapora . , 112 



XXIX. Holothurians, Synapta roseola, Synapta inhcerens, 



and Thy one briar eus . . . . . . .114 



XXX. Anatomy of Holothurian, Thyone briareus . . 117 



XXXI. Thyone briareus 133 



XXXII. ucumaria pulcherrima, Thyone unisemita, Thyone 



scabra, and Synapta inhtzrens, . . . .136 



