9s 



PBOF. P. M. DU>X'A> T ON THE OPH1URIDJE 



Beneath, no large scaling occurs, and the interbrachial spaces 

 are covered with slender, long-thorned stumps which diminish in 

 numbers towards the mouth-shields. 



Mouth-shields small, one third broader than long, either 

 lozenge-shaped or more or less rounded aborally and angular 

 orally, projecting on either side ; with a large adoral genital scale 

 attached on either side to the median line aborally. 



Side mouth-shields small, triangular, and not meeting adorally 

 to the mouth-shields. Jaw-angles short, broad, with a wide 

 median opening ; tentacular opening considerable, and the tentacle 

 long and papillose. Tooth-papillae small, crowded, especially 

 inferiorly, in a narrow blunt ovoid space. Teeth. Genital slits 

 large and reaching mouth-shields ; genital scale in contact with 

 slender geuital plate, broad, pointed orally and arched, shorter 

 than the plate. First lower arm-plate small, second as long as 

 broad, flat, re-enteringly curved adorally, with an aboral convexity. 

 Sides slightly incurved. The sixth plate is broader than long, 

 flat, almost rectangular, with a slight outward curve at the 

 sides ; further out, the plates have the aboral margin incurved, 

 and towards the tip of the arm the shape is preserved, but there 

 is a projection from the adoral edge towards the next or adoral 

 plate. Upper arm-plates broader than long, convex at the outer 

 margin, and concave and overlapped adorally, broadest at the 

 outer margin. Arms high in section and arched. Side arm- 

 plates large and flap-like, adding much to the under arm. A 

 tentacle-scale. Tentacles long, sharply papillose. Spines glassy, 

 nine near the disk, then seven, and six, which is the usual number, 

 not counting the hook which begins at the fifth joint. The three 

 lowest spines next to the trifid hook are short and small, the next 

 and the following are long, very broadly oar-shaped at the tip, 

 serrate, and with a crowd of long terminal spinules, especially on 

 one side (fig. 37) ; all are compressed. The uppermost spine is 

 shorter than the next and is a needle. The longer spines are 

 much longer than the breadth of an upper arm-plate. Diameter 

 of disk Smillim.; length of arm 50 millim., 1 to 6*25. Colour of 

 disk above d;irl< purple with light tints, the white stumps giving 

 r frosted appearance. Upper arm-plates each banded with white 

 along the aboral edge and with a Longitudinal while stripe ; 

 ground-tint ;i smalt-purple, and lines of it interfere with the 

 continuity of the white mark at the edge of the plates. Under 

 Surface of the disk white, with an Occasional Splash of purple in 



