REPORT ON THE ASTEROIDEA. 44] 
arranged in nearly regular longitudinal lines, the median radial series being larger than 
those adjacent on each side. Between the median series and the adambulacral plates on 
each side are three or four longitudinal series. The plates of the median radial series, 
which imbricate slightly, are more or less convex or crested transversely, and each bears 
three short, robust, cylindro-conical, obtusely tipped spinclets, the middle spinelets being 
placed rather more adcentrally than their lateral companions. ‘The surface of the plate is 
covered with a close-fitting membrane, upon which are borne two or three small isolated 
forcipiform pedicellariz. The plates of the most outward series are smaller, and bear 
normally one spinelet, but two may be present near the base of the ray, accompanied by 
one or two pedicellariz. These are succeeded by a second series of small plates similarly 
armed with one spine, which alternate with the first series. Then follows a series of large 
broader plates at the edge of the ray, which represent the supero-marginal plates; each of 
these bears two or three spinelets, one spine being placed on the middle of the plate and 
another near the inferior end of the plate; the latter appears somewhat isolated, and is 
borne either on a prolongation of the plate or on a small intermediate plate, but I am 
unable to state which without dissection. T'wo or three isolated, small, forcipiform pedicel- 
lari occur on all the plates, and each of the series is separated by a longitudinal series of 
single isolated papule. Immediately external to the adambulacral plates, directly contin- 
gent and not separated by any papule, is a longitudinal series of small plates which 
represent the infero-marginal plates. Hach of these bears a short, compressed, almond- 
shaped spinelet directed horizontally, forming a regular and conspicuous series of lateral 
spines standing at the extreme margin of the ray. One or two smaller pedicellarie stand 
at the base of this spine on the superior side. 
The adambulacral plates are very smal]. Their armature consists of two rather long, 
cylindrical, slightly compressed, obtuse spinelets, placed one behind the other, and forming 
two recular longitudinal rows. The outer series on the two sides of the ray are capable of 
entirely closing the furrow, masking the inner series of spinelets and the tube-feet. 
The madreporiform body is small and circular, and appears to occupy the centre of a 
rather large plate, the covering membrane of which terminates abruptly at the margin of 
the madreporiform body. Its surface is grooved with comparatively few fine striations. 
The larger apical plates on the disk bear two or three spines similar to those on the 
rays. A dorso-central, primary radials, basals, and under-basals, are distinguishable. 
The anal aperture is excentric. 
The ambulacral tube-feet, which are small and quadriserial in arrangement, have a 
fleshy, button-like, terminal disk. 
Colour in alcohol, a light orange yellow. 
Locality.—Station 219. Off D’Entrecasteaux Reef, North of the Admiralty Islands. 
March 10, 1875. Lat. 1° 54’ 0” S., long. 146° 39’ 40” E. Depth 150 fathoms. Coral 
mud. Surface temperature 84°:0 Fahr. 
(ZOOL, CHALL. EXP.—PART LI.—1888.) 56 
