THE STARFISHES OF THE HAWAIIAN ISLANDS. 
1041 
than the others, and forms a companion spine on all but first 4 or 5 plates. Sometimes a second 
spinule nearly equals it. General surface of plates is covered with spaced, sharp spinelets or thornlets, 
which are longest and stoutest along median transverse line, especially in vicinity of spines and spi- 
nules. A narrow area at inner end of plates, adjacent to adambulacrals, is usually free from spines, 
except on about 5 plates beyond the second to fourth. These have 3 or 4 sharp, short spinelets set 
close together in a comb, and pointed over the suture between inferomarginals and adambulacral 
plates, sometimes meeting 1 or 2 smaller spinelets on the latter, or arranged in a semicircle without 
opposing spinelets. These are rudiments of the peculiar pectinate pedicellarise characteristic of the 
genus, and which in this species are better developed on the actinal intermediate plates. 
Adambulacral plates have an acute angular projection into furrow, the spiniferous rim appearing 
semicircular. Greatest breadth is greater than length ; successive plates rather widely separated. Arma- 
ture as follows: (1) A furrow series of 8 (occasionally 6 or 7) slightly flattened, blunt spinelets. The 
4 or 5 median spinelets form a nearly straight series, are untapered and round-tipped. One or 2 spine- 
lets at either end of series are shorter than the central group of 4, and the lateralmost are shortest. 
(2) On actinal surface a tapering, stout, erect, pointed spine, a third longer than those of furrow 
series, stands in the middle of plate, and on an oblique line toward outer adoral corner is a companion 
spinule, much shorter and slenderer. A second slightly shorter spinule, near the aboral margin of 
plate, is in a longitudinal series with the last, while a similar third spinelet is sometimes found just 
aborally from the prominent spine. These 3 spinules are usually all present (but not always) and 
near base of ray either the first or second may be considerably enlarged. A row of 2 or 3 short, slender 
spinelets continues the furrow series along adoral margin of plate. 
Mouth plates prominent, broad, and the united pair strongly convex, with a wide free margin. 
Width of united pair exceeds interradial dimension. Each plate bears a marginal series of 7 flattened, 
tapering, blunt spines and spinules, disposed in a radiating horizontal series. The innermost spine is 
longest, the second slightly shorter, and the combined 4 stand out horizontally over peristome forming 
“teeth.” The remaining 5 spinelets are either graduated in length, or form an independent fan- 
shaped series at sides of the margin. On actinal surface a row of 5 or 6 prominent pointed spinules 
extends along margin of interradial suture, decreasing in length as they proceed outward. About 3 
widely spaced spinules are scattered between the above series and the marginals, often forming an 
intermediate series. 
Actinal intermediate plates are few and do not extend beyond fourth adambulacral. There are 8 
or 9 pectinate pedicellarise to each of the 5 interradial areas. These pedicellarise are situated over a 
suture between 2 plates, the 4 or 5 spinelets (making up comb) of one plate opposing an equal number 
of the adjacent plate, the suture running between them. The largest pedicellaria is that on inter- 
radial line. The others are smaller. There is considerable variation in the number of these pedicel- 
larise, the smaller specimen possessing but 2 to 4 to each interradial area, and lacking entirely the 
largest. Numerous delicate thornlets are scattered over intermediate plates. 
Anal aperture subcentral, small, but easily seen. 
Madreporic body of medium size, broadly elliptical, situated midway between center of disk and 
margin. Striations coarse, very irregular. 
Color in life unknown ; in alcohol ashy white. 
Young: The smallest specimen (station 4007) has R=ll mm., and r=3 mm., and a considerably 
different facies from the adult. The marginal plates are very broad and massive, and encroach upon 
the abactinal paxillar area. Paxillse relatively large, especially on disk. Adjacent to the margin in 
each interradius is a large, round paxilla, evidently the same as that which in the adult is situated 
about midway between margin and center of disk (basal plate of apical series). There is another 
smaller plate situated at the base of the ray, in the median line, which probably represents the radial 
plate. There is only 1 papular pore to each ray, just distad from the radial plate. Madreporic body 
minute. Spines of marginal plates small. No actinal interradial plates; no pedicellarise. Adambu- 
lacral plates widely separated. Furrow series of spinelets only 3 or 4; actinal adambulacral spinelet 
1, with an aborally situated companion. Mouth plates like adult, characteristic. A larger specimen 
with R=28 mm. has 4 or 5 actinal intermediate plates and a couple of pedicellarise to each area. 
There are scattered spinules on abactinal surface of disk, as well as on rays. 
Localities: Type (no. 21155, IT. S. National Museum) from station 3997, southwest of Kauai 
Island, 418-429 fathoms, fine gray sand and brown mud; bottom temperature 41°. Seven specimens 
