122 OPfllUKOIDEA. 



" Mouth-shields heart-shaped, one subpentagonal. Side mouth- 

 shields appear to be triangular ; they do not project inwards beyond 

 the median shields, and they meet each other in the position 

 usually occupied by the first under arm-plate, which is absent. The 

 other arm-plates are rectangular, with the inner and outer margins 

 somewhat rounded ; farther out on the arms they form an angle 

 so that the plate is hexagonal ; the lateral margins straight and 

 coincident with the attached margin of one of the tentacle-scales. 

 Side arm-plates slightly prominent where the spines are attached, 

 and meeting in the middle line either above or below. 



" Upper arm-plates transversely oval, but the proximal margin 

 instead of being evenly curved forms an angle. 



" Disk flat, thin, covered with small swollen overlapping scales, 

 which are coarser and radially elongated near the radial shields. 

 Radial shields wedge-shaped, very long, about four times as long as 

 wide, pointed at the proximal extremity, truncated distally, com- 

 pletely separated from each other, except perhaps at the extreme 

 outer end, by a median and one or two lateral rows of elongated 

 scales. Interbrachial spaces in the under surface covered with 

 similar small scales ; three, or sometimes at the proximal end of the 

 arm four, straight, tapering, bluntly-pointed arm-spines. 



" Two tentacle-scales, one towards the axis of the arm, elongated, 

 semi-oval, one on the proximal margin of the aperture, shorter and 

 more nearly circular. 



" Colour yellowish grey, with five rather indefinite radial mark- 

 ings on the dorsal surface of the disk. 



" The typical Amphiura bellis differs from this in having one 

 short stout blunt papilla on either side of the base of the mouth- 

 angle. It has also subtriangular mouth-shields, and the lateral 

 mouth-shields do not meet each other in the middle line. 



" The mouth-papilke are of a different shape. A first under 

 arm-bone is present, and the tentacle-scales of the first pair are 

 spiniform and rather conspicuous. 



" This single specimen is worthy of special notice, because the 

 species has been only known hitherto from specimens collected by 

 the 'Challenger' at Stations 174, near the Fiji Islands, and 232 

 and 236, off Japan. It is interesting to notice that Asteronyx 

 loveni is also common to the North European seas and those of Japan, 

 and a relation has been traced by Drs. Gwyn Jeffreys and Giinther 

 between the Mollusca and fishes of Japan and the North Atlantic 

 and Mediteranean." 



Dredged at 59° 40' N., 7° 21' W., 516 fms., during the cruise of 

 H.M.S. ' Triton.' 



4. OPHIACTIS. 



Opliiactis, Liitk. Vid. Medd. 1856 (1857), p. 12 ; Lyman, III. Cat.M. C. Z. 



i. (1865) p. 105 ; id. Chall. Rep. Oph. (1882) p. 112. 

 Ophiolepis, M. Tr. Syst. Ast. (1842) p. 89 (pars). 



No tooth-papillse ; teeth ; mouth-papillae few and small. Radial 



