PLATE XXVIII. 



1. Calamoerinus Diomedas. natural size, seen facing the right posterior interambulacrum. 



2. Piece of stem, natural size. 



3. Basal part of same, showing the expansion of the last joints ; asymmetrical view. 



4. Symmetrical view of basal joints of same. 

 ">. Enlarged view of upper part of stem. 



Specimen from 782 fathoms, Station 3357, off Mariato Point, February 24, 1891. 



