REPORT ON THE ASTEROIDEA. 231 
as to give the appearance of coarse velvet pile. The supero-marginal plates bear no 
spinelets. 
The infero-marginal plates correspond to the superior series, each plate being equal in 
length to its companion in the upper series. Their height, however, is slightly less, and 
they are well curved upon the actinal surface. Their surface is covered with short close- 
set papill similar to those on the supero-marginal plates, which become slightly larger 
and more spiniform at the end of the plate adjacent to the adambulacral plates. Each 
plate bears along the upper half of the aboral margin a series of four (normally, but some- 
times three) small tapering spinelets. The uppermost spine is the smallest, the rest sub- 
equal or with either the lowest or the median spine slightly longest. They are closely 
appressed to the side of the ray, and are directed at a slight angle upward : the position of 
the series on the plate being also sometimes very slightly oblique. 
The adambulacral plates are elongate, large, with a faintly convex margin towards the 
furrow. Their armature consists of a furrow series of six or seven rather long, delicate, 
cylindrical spinelets, equal in length, covered with membrane, and standing parallel to 
one another. ‘The series or “ combs” thus formed are distinctly spaced from the neighbour- 
ing series on adjacent plates. On the actinal surface of the plate and near to the marginal 
series is a longitudinal series of three or four spines, slightly shorter and more robust, 
widely and irregularly spaced ; and external to these is another longitudinal series of four 
or five similar spines, but even more irregular in disposition: indeed, so far is this carried 
in both cases that it is often impossible to distinguish any regular serial arrangement at all. 
Sometimes a few additional spinelets may be present, external to those above mentioned, 
and the grouped character becomes then more marked. These spinelets on the actinal 
surface of the adambulacral plate are covered with membrane like the marginal series, 
and they have generally a more or less straggling and irregular appearance. 
The mouth-plates are elongate and narrow, and the united pair form a convex keel 
actinally. Their armature consists of a marginal series of small, rather robust, and 
abruptly tapering spinelets, shorter than the marginal series on the adambulacral plates, 
about six or seven on the free margin of the plate, although others appear to continue the 
series up to the outer extremity of the plate. At the innermost point of each mouth-plate 
is one elongate, flattened and round-tipped mouth-spine, greatly exceeding any of the 
other spines in size, and the pair of spines at each mouth-angle are parallel to one another 
and directed towards the centre of the actinostome. At first sight these enlarged spines 
might be considered as the innermost spines of the marginal series above described, but I 
am doubtful whether this is really the case, as there is the singular occurrence in this form 
of a small group of short spinelets present on each plate at a still higher level than the 
foremost mouth-spines above mentioned, and this little insignificant group is further 
peculiar from the fact that it is not directed towards the centre of the actinostome, but in 
the direction of a line crossing the ambulacral furrow. If this group of small and abnor- 
