187 



DESCRIPTION OF A NEW OPHIURAN. 



By H. Farquhar. 



( C ommu^dcated hy the Secretary.) 



(Plate xv.) 



Ophioplocus Huttoni, n.sp. 



Diameter of disc 6 mm.; length of arms about two and a half 

 times the diameter of the disc; width of arms near the disc 1"2 

 mm. Disc round, slightly swollen, covered above and below with 

 rounded, irregular, imbricating scales; two or three small scales 

 in the centre of the disc surrounded by a rosette of five larger 

 ones, outside of these are rows of larger scales (about 0'5 mm. 

 wide), each of these larger scales surrounded by smaller, irregular 

 ones; one broad scale on the edge of the disc in the middle of the 

 interbrachial space; a number of very small scales where the 

 arms join the disc. Radial shields small (about 0-6 mm. 

 long), oval, far apart, sunk in the scaling of the disc. Scales on 

 the under side of the disc smaller than those above and more 

 regular, decreasing in size from without inwards. Mouth- 

 papillfe five on each side of the mouth-angle, crowded, the outer- 

 most and innermost pointed, the others squarish, the outermost 

 but one largest, others decreasing in size, the innermost one 

 smallest. Mouth-shields broad, fan-shaped. Side mouth-shields 

 oblong, broader without than within, meeting within. Under arm- 

 plates slightly broader than long, lateral and inner lateral sides re- 

 enteringly curved. First under arm-plate like the mouth-shields in 

 shape, but smaller. Side arm-plates well developed, bearing two 

 short rather stout, bluntly pointed arm-spines. Halves of upper 

 arm-plates near the base of the arms rounded, ana separated by 



