NO. 7 SEA-LILIES AND FEATHER-STARS CLARK 43 



Fig. 52. An arm of Stephanomctra echinus, showing the stout and spine- 

 like oral pinnules. 



53. An arm of Stylomctra spinifcra, showing the mid-dorsal overlap- 



ping spines. 



54. Four syzygial pairs from the arm of Stylometra spinifcra, showing 



the progressive increase in the individuality of the two elements 

 distally. 



55. Pentacrinoid larva of a large Feather-Star, Heliometra glacialis 



(after Levinsen). 



56. Ventral view of a larva of Antcdon Dicditcrraiica early on the eighth 



day (adapted from Bury). 



57. Myaostomum costatum, dorsal view (after Boulanger). 



58. The same, ventral view (after Boulanger). 



59. Galathea clcgans (after Potts). 



60. Cirolana lincata (after Potts). 



61. Cyclotclson purpurcum (after Potts). 



62. Scalpellum pcntacrinarum (after Pilsbry). 



PLATE 16 



A specimen of Ncniasicr ioivcnsis captured in shallow water in the 

 Bahamas (Cat. No. 36164 U. S. N. M.). 



