102 



PROF. P. M. DUNCAN ON THE OPIIIURJIXE 



small, and white. The mouth-shields are broader than long, 

 almost semicircular in their oral curve and more angular without. 

 Side mouth-shields large at the side and narrow, and not always 

 meeting orally. Jaw-angles short, much separated aborally, and 

 having large tentacular openings and very large papillose ten- 

 tacles. Teeth three in number. The tooth-papillae are in a 

 short oval, and the jaw-plate is very distinct. About ten to 

 twelve rather large tooth-papillae surround a line of from five to 

 seven small papillae, and the highest papillae are like a true tooth 

 split down the middle, and are therefore two in number. Strong 

 second genital scales in contact with the aboral edge of the mouth- 

 shields. Lower arm-plates feeble and thin, separated by some skin, 

 longer than broad, narrow and slightly incurved orally and aborally, 

 and broadest in their middle part near the disk ; but further out 

 the greatest breadth is near the aboral edge. A projection from 

 each side, often bifurcate, causes the above-mentioned breadth 

 and separates the consecutive tentacle-openings. Side arm-plates 

 large, composing most of the arm, flap-like and very projecting; 

 tentacle-openings close to the lower arm- plates, and opening below 

 and not at the side of the arm. Seven glassy, slender, and hollow 

 spines near the disk and far out, near the end five spines occur. 

 The lowest spine, at a short distance from the disk, is a com- 

 pressed, glassy, four- or five-pronged hook. The next three 

 spines are on the under surface of the arm, and are longer than 

 the hook, compressed and spinulose on both sides ; the next spine 

 is long, blunt, compressed, and has spinules near the top, some 

 being hooked and a few on the shaft. Upper spine a needle 

 either long or short, hollow. Longest spines longer than the 

 breadth of the upper arm, this is 2 millim., and the spines may 

 be 2'5 millim. The minutely squamous skin of the upper arm is 

 coloured with wide bands of light and dark purple dots. Arm- 

 bones formed to a certain extent after the type of Ophiothrix, 

 but presenting a tall umbo and no median peg*. No upper arm- 

 plates, and there is some nodulation far out in the arm at the 

 joints. Colour of the disk brown, with a dot or two of purple 

 ;ii the ends of the radial shields and on the mouth-shields, lower 

 scaling of disk opaque white. Diameter of disk 7 to S millim.; 

 length of arm 00 to SO millim. 

 Locality. King Island. 



* 060 p. 117 in the next communication. 



