THE STARFISHES OF THE HAWAIIAN ISLANDS. 
1039 
those on the outer edge of the plate being much slenderer and smaller than those adjacent to the fur- 
row series. The former sometimes form an irregular longitudinal series. The enlarged spinules 
usually stand in an obliquely longitudinal or even transverse series. 
Actinal intermediate plates extend as far as fifth inferomarginal. The series adjacent to adambu- 
lacrals is much the largest. Each plate bears near the center 1 (occasionally 2) lanceolate, sharp, 
flattened, appressed spinule surrounded by well spaced, small spinelets which increase in size from 
the edge toward center of each plate. The peripheral series is slender, but the more centrally situated 
spinelets are clavate with flattened, subsquamiform tips. There appear to be rudimentary fascioles 
between the plates, especially those adjacent to adambulacral series. The granules become more 
flat-topped and subsquamiform near the inferomarginals. 
The armature of the mouth plates is robust, consisting of a furrow series of stout, curved, round- 
tipped spinelets, slightly compressed, which are subequal in size, or a trifle smaller at the inner third 
of the series, and a trifle larger than the corresponding spinelets of the first adambulacral plate. There 
is an odd spine at the inner end of the combined pair, in addition to the regular marginals. There is 
a regular series of about 9 along the margin of the median suture, the inner 2 or 3 spinelets round- 
tipped and of about the same size as the adjacent furrow spinelets, the outer graduated and bluntly 
pointed, clavate or papilliform. The furrow series is continued along the margin adjacent to the first 
adambulacral, in 5 or 6 smaller spinelets, which increase in thickness toward the outer end of the 
plate. 
Superambulacral plates present, feebly developed ; lacking beyond eighth inferomarginal. 
Madreporic body small, nearly hidden by paxillse, situated very nearly midway between center 
of disk and inner edge of superomarginal plates. 
Color in alcohol, bleached yellowish. 
Locality: Type (no. 21159, U. S. National Museum) from station 3474, south coast of Oahu Island, 
cruise of 1891, 375 fathoms, fine white sand, 2 specimens. 
This species differs from the foregoing in having larger rays, more prominent paxillse, which are 
very regularly arranged, one or two enlarged spinules on each actinal intermediate plate, and either 
one or two enlarged spinules on all the adambulacral plates. It bears closest resemblance to Pseudar- 
cliaster tessellatus Sladen, from Simons Bay, Cape of Good Hope. From this species it differs in having 
shorter and wider mouth plates, which appear, in addition, to be relatively smaller. The 2 lineal 
series of spinelets are not subparallel, but outline a triangle, the base of which is the superficial series 
adjacent to the median suture. The marginal plates encroach more upon the dorsal and ventral areas, 
especially in the case of the inferomarginals. The granulation of the latter is coarser than that of 
superomarginals, instead of being of uniform size, as in tessellatus. The furrow series of spinelets is 
coarser, and there are usually 2 actinal spinules, instead of 1 on each adambulacral plate. The 
abactinal paxillse contain more spinelets, and appear to be slightly larger, and the madreporic body 
is much smaller or at least less exposed. This form is also related to Ps. mozaicus Alcock from the 
Indian Ocean, but differs in having shorter rays, which are broader at the base, less numerous marginal 
plates, and actinal interradial plates which extend to the fifth, instead of tenth, inferomarginal. 
Minor differences are apparent in the armature of the mouth and adambulacral plates. 
A second specimen has the following measurements: B,=59mm.; r=15 mm. E=3.9r. Thus the 
rays are a trifle longer than those of tessellatus, and judging from the figure in the Challenger report 
(Asteroidea, pi. xvii, figs. 3 and 4) are also more robust and more gradually and evenly tapered 
from the interbrachial arc. a 
Family BENTHOPECTINID^ Verrill, 1899. 
Benthopectinidse Verrill, Revision of certain genera and species of starfishes with descriptions of new forms. <Trans. 
Conn. Acad. Sci., vol. x, 1899, p. 217. = Pararchasterinae Sladen. 
Subfamily P0NTASTEEIN51 6 Verrill, 1894. 
Pontasterinae Verrill, Descriptions of new species of starfishes and ophiurans, etc., <Proc. U. S. Nat. Mus., xvii, 1894, p. 
246. 
a After this report was completed and had left my hands three species, Ps. peclinifer, Ps. pulcher , and Ps. verritti, were 
described by Ludwig (Mem. Mus. Comp. Zool. , Vol. xxxii, J uly 17, 1905, p. 106-120) . Ps. jordani resembles the first two forms, 
but lacks any structures that might be considered pedicellariae. From pulcher, jordani differs, also, in having actual 
intermediate spines, and a much more extended papular area, reaching to supermarginal plates and interradial line. 
Ps. pectinifer is from Gulf of Panama, and pulcher from southwest of Acapulco, and vicinity of Galapagos Islands. 
b Classified by Verrill under his Plutonasteriuee. The present classification is that advocated by Sladen in “Chal- 
lenger Asteroidea.” 
F. C. B. 1903, Pt. 3—18 
