; REPORT ON THE ASTEROIDEA. 9 
The mouth-plates are large, prominent, and convex actinally, presenting a broad and_, 
rounded, but centrally rather flattened, margin towards the actinostome ; and the median 
suture of the pair is imperfectly closed. Their armature consists of a marginal series of - 
five mouth-spines on each plate, the innermost one being twice or three times as long and 
robust as the others, which are subequal and rather widely spaced. On the actinal surface 
of each plate are three (or sometimes only two) robust tapering spinelets, standing wide 
apart and forming a line parallel to the median suture; these do not appear to attain 
the size of the superficial actinal spinelets on the adambulacral plates. The surface of 
the plates is covered with membrane, and no other spinelets are present. 
The actinal interradial areas are of very small extent, and do not reach beyond the 
fifth adambulacral plate. The size and number of the intermediate or ventral plates is 
undeterminable in spirit specimens on account of the membrane with which they are 
overlaid. So far as can be judged, they appear to be comparatively large, and are 
certainly few in number. A few of these bear one, or occasionally two, small spinelets 
1°5-2 mm. in length. 
The anal aperture is subcentral but indistinct, surrounded by large spinelets. 
The madreporiform body, which is large and oval, is situated midway between the 
centre of the disk and the odd interradial supero-marginal plate. Its surface is slightly 
convex, finely grooved with numerous highly convoluted striation furrows, and has on 
that account a remarkable resemblance to the “brain” coral. Several large spinelets 
surround its margin, the largest being at its adcentral end. 
The papulz are very small and numerous, but confined to an area at the base of the 
rays, which does not extend beyond the fourth supero-marginal plate. The area occupies 
nearly the whole breadth between the supero-marginal plates, and extends well upon 
the disk, but no papule are present along a broad band which traverses the median 
interradial line. 
No pedicellarize of any kind are found upon this species. 
Colour in alcohol, a dirty bleached ashy grey. 
Individual Variation.—There is a fragmentary specimen from Station 235, in a very 
bad condition, of a much smaller example than the type above described, in which the 
spines of the actinal surface generally are proportionately much more delicate. From 
their length and character, I am disposed to consider this a feature of individual or even 
locational variation, rather than a phase of growth; a remark, however, which is merely 
conjectural, for its validity could only be proved by the examination of a large series of 
specimens. 
Localities. —Station 237. Off the coast of Japan, south of Kawatsu. June 17, 1875. 
Lat. 34° 37’ 0” N., long. 140° 32’ 0” E. Depth 1875 fathoms. Blue mud. Bottom 
temperature 35°°3 Fahr.; surface temperature 73°0 Fahr. 
(ZOOL. CHALL. EXP.—PART LI.—1887.) 
bo 
