REPORT ON THE ASTEROIDEA. 449 
longer than the diameter of the disk, robust, broad at the base, and tapering to the 
extremity, slightly convex actinally. Interbrachial arcs acute. 
Abactinal area with plates forming a reticulated network with wide meshes. The 
plates bear at widely spaced intervals tubercular eminences, on which are borne paxilliform 
tufts of four or five spinelets, which are robust at the base, tapering to a point, about 
3 mm. in length, and usually all drawn together at the tip like a paint-brush when 
moistened and drawn to a point. No order of arrangement is discernible in the dis- 
position of the paxille. Large isolated papule are present in the meshes, five, six, or 
even more, in those which are largest. These are remarkable from the fact that the 
margin of the orifice is beset with a ring of round, granule-like, fleshy papille, groups of 
which also occur on the intervening membrane, giving it a more or less verrucose appear- 
ance. The papul also appear to be delicately verrucose. 
The marginal plates (? supero-marginal) form a regular and well-defined longitudinal 
line, and each bears a tuft of five or six spinelets rather longer and more robust than 
those on the abactinal paxillae and appressed to the ray, the direction being nearly hori- 
zontal and outward. ‘This series of plates is separated by a rather wide and well-defined 
space, occupied by smooth membrane, from another perfectly regular longitudinal series 
of plates situated midway between the supero-marginal plates and the adambulacral plates, 
and consequently midway on the actinal surface of the ray. These are either infero-marginal 
plates or actinal intermediate plates, but [ am unable to say definitely which series they 
represent without mutilating the single example; I am inclined to rank them as inter- 
mediate plates. The plates in question are armed with a flat comb of four or five spinelets, 
similar to those on the marginal plates above described, more or less appressed to the ray, 
their direction being usually oblique and outward at an angle of about 45° to the line of 
the furrow. 
The adambulacral plates are large and broader than long. Their armature consists of 
two series of spinelets. (1.) An inner or furrow series of seven or eight delicate, rather 
elongate, tapering spinelets, the outermost of the series rather smaller than the others, and 
all united for about half their length by a membranous web, forming a rather elongate, 
semicircular scoop or fan, the membrane extending uninterruptedly upon and covering the 
plate. (2.) Far back on the actinal surface of the plate is an oblique flat comb of four 
elongate, pointed spinelets, much larger and more robust than the furrow series, and 
similar to the spinelets on the actinal intermediate plates above described. They are 
appressed to the ray, their base line is oblique in position on the plate, and their direction 
is outward and at an angle of about 45° to the line of the furrow. The series of these 
actinal spines forms a regular longitudinal line along the ray. There are thus three regular, 
distinctly spaced, longitudinal lines of combs of spines visible on the actinal surface of 
the starfish. 
The mouth-plates are very large, and have an elongate median eminence along the line 
(ZOOL. CHALL, EXP.—ParRT L.—1888.) 57 
