REPORT ON THE OPHIUROIDEA. 127 



(Type specimeu from Station 188.) Diameter of clisk 15 mm. Length of arm about 

 135 mm. Width of arm, close to disk, without spines, 2'5 mm. One very large square 

 mouth papilla on each side of the angle, and a pair much smaller and more rounded at 

 the apex ; besides these, there may be distinguished a minute papilla outside the great 

 flat one. Mouth shields large, and much curved within, and prolonged by a rounded lobe 

 without. Side mouth shields very small, pear-seed shape, with the smaller end inward ; 

 they occupy the inner lateral sides of the mouth shield, and are widely separated. Under 

 arm plates four-sided, broader than long, outer and inner edge slightly curved, and with 

 feeble re-entering curves on the lateral sides. Side arm-plates short and high, scarcely 

 prominent, meeting neither above nor below. Upper arm-plates small, little swollen, nearly 

 round ; but some distance out on the arm they are broader than long. Disk round, flat, 

 and rather thick, having a notch over each arm ; surface covered above and below with 

 rather large, rounded, swollen, loosely overlapping scales, those in the interbrachial spaces 

 being slightly larger. Radial shields pear-seed shape, little swollen, with a peak inward, 

 separated their entire length by a row of three elongated scales, the inner one being 

 surrounded by several much smaller. On the outer edge of the radial shields there is a 

 row of small scales continuous with those on the margin of the disk. There are ten 

 stout, pointed arm spines, the two lowest being about twice as long as the others, much 

 sharper, and usually curved. Two very large flat tentacle scales with curved edges, one 

 on the inner margin of the tentacle pore, which overlaps the one on the edge of the under 

 arm plate. Colour in alcohol, straw. 



Station 188.— September 10, 1874 ; lat. 9° 59' S., long. 139° 42' E ; 28 fathoms ; mud. 



AmpMura hellis, Lym. (PI. XVIII. figs. 4-6 ; PI. XL. figs. 16-18). 



Amphiura hellis, Lym., BuH Mus. Comp. Zool, vol vi., isart 2, p. 19, pi. xi. figs. 282-284, 1879. 



Disk covered above and below with delicate scales ; two tentacle scales. Radial 

 shields narrow, about three times as long as wide ; four straight tapering arm spines ; 

 upper arm plates thin. 



(Type specimen from Station 232.) Diameter of disk 7 mm. Arm long, slender, and 

 tapering gradually ; its width next to the disk is 1 mm. One stout, short, blunt papilla 

 on either side of the base of mouth-angle, and a pair, stout and bluntly pointed, at its 

 apex. The tentacle scales of the first pair are spiniform and rather consj)icuous. Mouth 

 shields small and rounded, with sometimes a rounded angle within and a slight lobe 

 without. Side mouth shields three-sided, c^uite broad without, tapering within, where 

 they do not meet. First under arm plate six-sided and rather larger than usual ; those 

 beyond squarish, about as long as broad, with outer side nearly straight, lateral sides a 

 little re-enteringly curved, and usually a very short truncated angle within. Side arm 

 plates small, and not strongly projecting, meeting neither above nor below. Upper arm 

 plates thin, of a pretty regular transverse oval shape, with lateral corners well rouuded. 



