512 



COLLECTIONS FROM THE WESTERN INDIAN OCEAN. 



Neoplax ophiodes. (Plate XLV. figs, a-e.) 



Disk pentagonal and small ; arms narrow, elongated, having the 

 general appearance of being somewhat constricted between each 

 joint, owing, probably, to the mode of attachment of the spines to 

 the edge of the side arm-plates. Granules on the disk rather large, 

 sparse, scattered, sometimes almost glassy in appearance ; at the edge 

 of the disk they are more closely packed and form a pretty definite row 

 of bounding granules. Very few granules on the actinal surface. 



Mouth-plates oval, a good deal broader than long, the side mouth- 

 shields lying across them, so as almost, or altogether, to meet in the 

 middle line. Five mouth-papillae, four close together, the fifth 

 close to its fellow of the opposite side. Three or four pretty strong 

 teeth. 



Though the genital slits are ordinarily long, the bridge separating 

 the fellows of a pair is of a fair breadth : genital scale prominent. 



On the fourth or fifth joint from the disk there are six small 

 but distinct lateral spines, attached to the edge of the lateral plate ; 

 and further out there may be seven spines. The lowest spine is 

 the longest and the most distinct. The upper arm-plates are widest 

 along their proximal edge, the sides slope inwards, and the distal 

 edge is much narrower. The most distinctive character in the 

 lower arm-plates appears to be the excavation on the distal edge. 

 The tentacle-scale is single, small, and at times, indeed, appears to 

 be absent. 



Diam. of disk 11*5, 8. Length of arm (probable), GO, 40 millim. 



Coloration : the three specimens exhibit some differences, but are 

 all brownish above and of a lighter hue below ; several arm -joints 

 are, here and there, darker than those just in front of or behind 

 them. 



All the three specimens were found at Darros Island, Amirante 

 group, at a depth of 22 fms. 



