274 RECENT OPHIURANS. 



areas between the arms covered with somewhat small scales each of which bears 

 a slender spinelet; towards the mouth the scales disappear and the area is covered 

 only by a thin naked skin. Radial shields rather large, smooth, separated from 

 each other by a longitudinal series of 4-6 scales. Upper arm-plates quadri- 

 lateral; proximal margin short, straight; distal margin much longer, broadly 

 convex and slightly thickened or swollen; lateral sides slightly concave; the 

 plates are thus somewhat fan-shaped; they are at first wider than long but 

 become longer than wide and they are in contact the full width of the proxi- 

 mal margin. Oral shields nearly twice as wide as long, diamond-shaped with 

 rounded angles. Adoral plates rather large, triangular with blunt and rounded 

 angles, meeting within. Under arm-plates nearly rectangular, longer than 

 wide, broadly in contact. Side arm-plates moderate; each carries 3-5 (usually 

 4) slightly thorny, glassy arm-spines; uppermost or next, longest and rather 

 exceeding two arm-joints; lowest slender but rough pointed. Tentacle-scale 

 scale-like, rather large for an Ophiothrix. Color (dried), pale olive, distal tips 

 of radial shields with white markings ; upper surface of arm with a narrow median 

 pale brownish stripe bordered on each side with a broader white stripe which is 

 bounded on the outer side with a narrow dai'k olive line; on each upper arm- 

 plate the white bands widen a little but abruptly narrow again as they pass 

 onto the next plate; oral region and lower surface of arms nearly white. 



HoLOTYPE (M. C. Z. 3800). Torres Strait: Murray Islands, Mer, south- 

 western reef, on under side of a coral fragment. Oct. 27, 1913. Carnegie 

 Exp. 1913. H. L. Clark coU. 



It is possible that this species ought to be put in Ophiotrichoides but after 

 comparing it with the tjrpe species of that genus, I do not feel satisfied that the 

 two are congeneric, and prefer to leave this new species in Ophiothrix until that 

 genus is divided into its component parts, when the real relationships will more 

 easily be brought out. In life there were orange-colored marldngs on the upper 

 siu-face of the arms, but as the specimen was taken only a few hours before 

 leaving Mer, when all our apparatus was packed up and time was precious there 

 was no opportunity for a sketch to be made or even for careful notes on the color- 

 ation to be taken. 



832. 0. LONGIPEDA (Lamakck). 



Ophiura longi-peda Lamaeck, 1816. Anim. sans Vert., 2, p. 544. 

 Ophiothrix longipeda Mulleb and Troschel, 1842. Syst. Ast., p. 113.' 



' Herklots (1869. Echinod. peintes d'apres nature, pi. 7) gives a colored figure purporting to be 

 0. longipeda, but as it is totally unUke any longipeda which I have seen either Uving or preserved, I feel 

 confident that it represents a different species. 



