THE STARFISHES OF THE HAWAIIAN ISLANDS. 
1081 
This species is characterized especially by the very prominent abactinal plates, many of which are 
naked centrally and form well-rounded bosses along the rays; also by the form of the pedicellarise 
and the character of the adambulacral armature, which is disposed in 3 series, the median being 
smaller than either the outer or inner. In the latter feature this species bears a certain resemblance 
to 0. tuberifer Sladen, but is otherwise quite different, as may be seen by comparing figures. Although 
the type is still probably young, the characters appear to be sufficiently well marked to merit descrip- 
tion. The name refers to the 3 series of adambulacral granules. 
Ophidiaster sclerodermus, new species. 
PI. XXX, figs. 4, 4a; pi. xxxi, figs. 2, 2a. 
Rays 5. R=63mm.; r= 13 mm. R=4.8r. Breadth of ray at base, 15-16 mm.; at middle of i ay, 
10 mm. Height of ray at base, 10 mm. 
Disk decidedly large for genus; rays only moderately long, tapering from a fairly broad base (for 
the genus) very gradually to a blunt extremity, which is tipped by a prominent terminal plate. The 
rays are decidedly broader at base than elsewhere, and measured along its side each ray is 3 2 times 
longer than broad. The interbrachial angles, about 75° to 85°, are not sharp. Abactinal surface 
convex, but only slightly so in middle of disk; actinal surface nearly plane, the inferomarginal plates 
forming a well-rounded border to the area. No papulae on ventral surface. 
The plates are prominent on abactinal and lateral surfaces, the longitudinal series being separated 
by prominent but shallow papular furrows. The transverse divisions between the plates are not nearly 
so evident, the plates themselves being entirely hidden by the finely granular, thick skin. One can 
distinguish readily a radial series, and on either side an adradial, a supero, and inferomarginal, the 
superomarginal defining border of ray when viewed from above. Between the inferomarginal and 
adambulacral series there are, at base of ray, 3 series of smaller intermediate plates, which are reduced 
to 2 beyond the proximal third of ray and to 1 on distal third. There are no papular pores between 
these plates. Whole body is covered with a remarkably tough, thick skin, which is closely covered 
with a uniform, very fine granulation. Although this specimen is many times larger than the type 
of 0. lorioli, the granules are actually much smaller. On the outer third of the ray the plates are 
frequently irregular in disposition, and on 1 ray of the type the plates are all irregular, as if from some 
sort of injury. Papular areas form 6 longitudinal series; 9 to 14 pores to an area on proximal two- 
thirds of ray, but on the distal portion fewer; and frequently there many papular areas are absent. 
The pores are many times larger than the granules, which are here a trifle larger than on the plates. 
The pores form irregular stenciled lines, resembling letters or simple hieroglyphics. There are few 
papular areas in the central portion of disk. Small 2-jawed entrenched pedicellarise are abundant. 
Each consists of 2 narrow, spatulate, smooth blades, set in a little pit and lying each in a specialized 
depression with a smooth, rounded border. The whole apparatus is 1.5 mm. long, and the jaws are 
usually curved, making it crescent-shaped. On the proximal part of ray a series of 3 to 12 of these 
pedicellarise are present just external to the outer adambulacral spinelets, and they are widely scat- 
tered on the marginal and abactinal plates, 1 to a plate, but are most numerous in the proximal 
regions. Occasionally a pedicellaria has 3 jaws. 
Furrow spinelets, 2 to a plate, are much flattened, rounded-truncate, subequal, or the adoral is a 
shade narrower at the base. They are about twice as long as broad and the adoral is usually a little 
broader at the tip than at the base. The furrow face is flat or a trifle concave near base. External to 
these spinelets, at a distance equal to one-third or one-half their length, is a regular series of equidis- 
tant, somewhat flattened, broadly ovoid tubercles, the exposed portion of which is about two thirds 
the length of the furrow spinelets, of which about 3 correspond to 2 tubercles. Packed closely about 
the tubercles and filling the space between them and the furrow are many roundish or compressed 
granules, a trifle larger than the rest of actinal granules. Here and there one can distinguish lines, 
bordered by slightly larger bead-like granules, running out from the furrow toward the marginal 
plates, and similar fainter lines can be distinguished, with the aid of a glass, between many of the 
plates themselves. The mouth spinelets are like the adambulacral but a trifle larger. 
Madreporic body-inconspicuous, but fairly large, cordiform or shield-shaped. Striations fine, 
interrupted, branching, centrifugal. The plate is perfectly flat and is situated nearer margin than 
center. Anal aperture is surrounded by a number of considerably enlarged granules. 
