REPORT ON THE ASTEROIDEA. 467 
two or three should be counted as belonging to the adambulacral plates. The question 
can only be decided by dissection and preparation, a step which would entail greater 
mutilation than I consider desirable in the case of a unique specimen. ‘The plate upon 
which the outer spinelets are borne is slightly curved upward to the margin. 
The mouth-plates are prominent, with an elevated angular keel along their line of 
juncture, terminating aborally in a rounded but prominent peak. The adoral margin 
projects into the actinostome, but its prominence is masked by the position of the three 
mouth-spines proper which stand on each side. The innermost is the longest, and 
situated close to the adoral peak; the other two are smaller, the outer one being the 
least. At the outer angle of the plate adjacent to the adambulacral plate are three small 
spinelets placed in a semicircle, which should probably also be ranked as mouth-spines. A 
single large secondary mouth-spine is placed on the surface of the plate immediately 
behind the innermost of the marginal mouth-spines, and is both longer and stouter than 
these. All the mouth-spines are enveloped in membranous sheaths, those of the two 
inner mouth-spines and the secondary being thick and fleshy, the others more delicate and 
with saccular prolongations. 
The madreporiform body is very large and irregularly suboval in outline, the margin 
being festooned by prolongations, having the appearance of flowing out between the widely 
spaced fascicules by which the plate is surrounded. The central portion is slightly 
elevated, subconical rather than convex, and somewhat undulating in conformity with the 
marginal projections. The surface is covered with numerous very fine striations, which 
radiate from the centre. The major axis of the body measures 9 mm., and the minor 
75mm. Its position on the disk is somewhat nearer the centre than midway between 
that point and the margin. 
A large aperture, 2 to 2°5 mm. in diameter, exists at a considerable distance from the 
centre ; a muscular ring is traceable, and some cecum-like structures are slightly protruded. 
This is probably the anal aperture, but its very excentric position is remarkable, being 
nearly midway between the centre and the margin, and when the madreporite is placed 
in the right anterior interradium, a line drawn through the centre of that plate, parallel 
to the antero-posterior axis of the starfish, would bisect the orifice. 
No pedicellariz are present. 
The ambulacral furrows are very wide, and the tube-feet form by crowding four rows; each 
tube-foot is furnished with a fleshy, button-like, terminal disk somewhat larger in diameter 
than the adjacent portion of the tube, and the centre shows an invaginated depression. 
The actinostome is large, measuring about 13°5 mm. in diameter, and the mouth-plates 
could not be apposed. 
The actinal interradial areas are very limited, and any additional intermediate plates 
that may be present beyond the representatives of those entering into the composition of 
the ray are very few in number. 
