Plate 52. 

 1-4. Asthenosoma coriaceum A. Acj. ; ''Challenger " Station 173. 



1. Abactinal system of specimen 125 niui. in diameter. 



2. Abactinal part of left posterior ambulacrum and interambulacrum, seen from dw| 



interior ; same specimen as fig. 1. 



3. ]*art of left posterior ambulacrum and interambulacrum of same specimen, seen froal 



the abactinal side. 



4. The same as fig. 3, seen from the interior. 



