10 



OPHIOCERAMIS ALBIDA. 



out spines, 3° 



Fig. 85. 



Description of an Individual. — Diameter of disk, 9°™ . Width of arm with- 

 Length of arm, 32°™-. Mouth-papilla? thirteen to each 

 angle, .all similar, blunt, rounded, spiniform ; the outer ones 

 largest, and all standing on the jaws, except the outer one 

 on either side, which touches the side mouth-shield. Mouth- 

 shields longer than broad, oval with a peak inward ; length 

 to breadth, 1.5 : 1. Side mouth-shields meeting within, 

 strongly bent outwards. Under arm-plates hexagonal, with 

 an angle towards each side ; lateral sides re-enteringly 

 curved ; length to breadth, 1 : 1.2. Side arm-plates not 

 prominent, and not meeting either above or below. Upper 

 arm-plates rudely hexagonal, wider than long ; length to 

 breadth, 1:2. The first two or three are small, and more or less distorted 

 by the encroachment of irregular supplementary scales or plates. Disk 

 covered with large plates, whereof a portion only ai'e sur- 

 rounded by smaller ones. On the back and in the centre 

 a conspicuous rosette of the six large primary plates, partly 

 separated by some minute ones; from these radiate single 

 lines of plates in each interbrachial space, separated by 

 smaller ones from the radial shields. The interbrachial 

 spaces below are covered by large imbricated plates and wide genital scales. 

 Radial shields wide, triangular, strongly diverging, touching by their outer 

 ends ; separated by a wedge of a large and a small scale ; length to breadth, 

 2.1 : 1.8. Arm-spines four, short, rounded, tapering, of about equal lengths, 

 1.2°"°'. Tentacle-scales rounded, standing close together on the side arm- 

 plate ; and outside them is a lip or little ridge. 

 Color, in alcohol, white. 



Hassler Expedition ; Barbadoes, 100 fathoms. Dr. William Stimpson ; Cape 

 San Antonio, Cuba, 424 fathoms. 



Fig. 86. 



Ophioceramis albida. 



Amphipholis albida, Ljdngman. Opliiuroidea Viventia, 314. 



PI. III. f. 29-31. 



Many specimens Avhich agree with the descriptions and with my notes 

 on the originals at Stockholm were brought from moderate depths in the 

 neighborhood of Rio La Plata. As Ljungman has suggested, the species 

 comes under Ophioceramis. 



