REPORT ON THE ASTEROIDEA. 313 
This is as follows: On the lateral margins of the plates, 7.¢., at right angles to the furrow 
are a series of spinelets which have the appearance of being in direct continuation of the 
furrow series above described ; they are not compressed, however, but papilliform, and they 
decrease in size as they recede from the furrow. A few similar papilliform spinelets pro- 
ceed along the outer extremity and thus complete a series surrounding the whole margin 
of the plate. Those on the lateral margins are slightly inclined over the rather wide 
furrow that separates adjacent plates towards the corresponding series of spinelets on the 
next plate. The adambulacral plates being very broad on the inner part of the furrow 
there are about seventeen or eighteen spinelets on the lateral and furrow margins there ; 
the proportion of breadth decreases as the plates proceed along the ray and the number of 
spinelets is consequently less, being about thirteen or fourteen near the middle of the ray. 
The adambulacral plates on the inner part of the ray have a single lineal series of four or 
five small spinelets standing on the median line of their area, parallel to the lateral margins, 
and consequently obliquely transverse to the furrow. Further out additional spinelets 
occur on the outer part of the plate, and there is a tendency to form two converging series, 
the point of the wedge being towards the furrow. One of the spines near the outer end of 
the plate is longer than the rest, very delicate, tapering, and sharply pointed. This minute 
spinelet is continuous throughout the series, excepting the innermost three plates and at 
the extreme tip. 
The actinal interradial areas are very small and triangular in outline. They are 
occupied by a comparatively small number of rather small plates, the margins of which 
are beset with moderately elongate papilla, with one or more in the centre ; all the spinelets 
are of equal length, rather wide apart, and stand nearly vertical, which gives the plates 
a somewhat paxilliform character, though the armature would be more correctly described 
as forming a rather widely spaced group. 
The mouth-plates are small and elongate, with nine or ten spinelets on the free margin; 
the outermost three or four of this series are compressed and truncate, the rest cylindrical, 
tapering, and sharply pointed, and the innermost are the longest. A lineal series of about 
eleven small spinelets runs parallel to the median suture, the innermost nearly as long as 
the marginal series, whilst the outermost are merely papilliform granules. On the margin 
adjacent to the adambulacral plate is a series of five or six spines, which rapidly diminish 
in size as they proceed outward, and do not always extend as far as the median series above 
mentioned. At the widest part of the plate there is an intermediate series of about four 
spines midway between the outer series of spines and that adjacent to the median suture, 
and parallel to the latter. | 
The well-defined pentagonal area of the abactinal paxille is slightly inflated, especially 
in the radial regions, the character being there emphasised by a slightly depressed central 
area, from which shallow channel-like continuations extend along the interradial lines, but 
die out before reaching the margin. 
(ZOOL, CHALL. EXP.—PART LI.—1888.) 40 
