1050 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Adambulacral plates are subquadrate with a slightly convex margin to furrow. Armature as 
follows: (1) A furrow series of 7 or 8 slender, parallel, round-tipped or truncate spines, strongly flat- 
tened in a plane crosswise to furrow. The central spine is longest, the series being graduated toward 
either end and forming an elegant and regular comb with a strongly convex edge. The lateral spines 
are somewhat tapered, and all are united for a short distance above the base by a thin web. (2) On 
the actinal surface, well spaced from furrow series, a longitudinal row of robust, 4-sided, round-tipped, 
or truncate spines, either tapered or not. They are stouter, but scarcely so long as the longest furrow 
spine. Proximal plates have 5 spines, the laterals being very short, scarcely more than granules. 
Throughout the greater part of the disk there are 3 subequal spines, with a granule at the adoral 
end of the series and sometimes a smaller spine to the aboral. These become reduced to 2 more 
tapering and roundish spines on the outer part of the ray. Along the outer margin of plate is a regular 
series of 4 to 6 irregularly prismatic granules, with 1 or 2 continued along the transverse margins for a 
short distance. An odd spinelet is sometimes present on proximal plates of the series, on the adoral 
margin, between the furrow and first actinal series. 
Mouth plates of fair size but not prominent, with a truncate outer end, and a long narrow margin. 
Actinal surface is slightly convex, rising toward the medium suture. Armature: (1) A furrow series 
of 13 (to 15) round-tipped, strongly compressed spines, which increase in size toward the inner end of 
plate. The series is not evenly graduated, the inner 3 or 4 spines becoming suddenly longer than the 
others, which are subequal in length with the furrow spines of the first adambulacral. (2) Parallel 
with the furrow series is a row of 6 to 8 spines similar to the actinal spines of adambulacrals, and 
forming a linear series with them. The outer portion of the plate is covered with flat-topped, polygonal 
granules, a superficial series along the margin of the median suture being usually evident. 
Actinal interradial areas are large and paved with irregularly polygonal, quadrate, or roundish 
plates which decrease in size toward the margin and extend along the ray to sixteenth. inferomarginal, 
or to within 15 mm. of the tip. Beyond the eighth inferomarginal there is but a single series. The 
plates are covered with numerous low, spaced, thimble-shaped granules, some of which, on the periph- 
ery, tend to become quadrate. The granules do not quite attain the edge of the plate, so that a 
conspicuous shallow furrow surrounds each group of them. On many of the plates of the series 
adjacent to adambulacrals is a small, 2-jawed pedicellaria similar to but larger than those of the 
abactinal surface. They have narrow spatulate blades. A few are scattered over the remainder of 
actinal intermediate area. 
Madreporic body of medium size, larger than the surrounding paxilke, situated nearer center than 
midway between it and margin of disk. Striations irregular. 
Color in alcohol, pinkish gray to pinkish brown. 
Variations: The cotype differs from type principally in having the superomarginals separated 
throughout the ray, the distal 5 to 7 by only a single series of abactinal plates. The paxillse crowns 
are slightly more convex, and fewer of them bear entrenched pedicellariae. 
Localities: Type (no. 21161, U. S. National Museum) from station 4134, west coast of Kauai Island, 
324-225 fathoms, fine coral and volcanic sand; bottom temperature 43.3°. Taken also at 4132, same 
locality, 257-312 fathoms, fine gray sand and mud. 
Judging solely by external appearances, the Pentagonaster arcuatusoi Sladen (Challenger Asteroidea, 
p. 277, pi. lii, figs. 1 and 2, pi. xvm, figs. 5 and 6) appears to be related to the present form, although 
the former may be a Mediasler. It is not possible to tell exactly until the structure of the abactinal 
plates is known. Arcuatus is not a Pentagonaster in the restricted sense. 
Named for Hon. George M. Bowers. 
Subfamily GONIASTERDLE Verrill, 1899. 
Goniasterinse Verrill, Revision of Certain Genera and Species of Starfishes, with Description of New Forms. <Trans. 
Conn. Acad., x, 1899, p. 200. 
Genus PENTAGONASTER Gray. 
Pentagonaster Gray, Ann. N. H., vol. vi, 1840, p. 280. Type, P. pulchellus Gray. 
Aslrogonium (pars) Muller and Troschel, System der Asteriden, 1842, p. 55. 
Stephanaster Ayres, Proc. Boston Soc. Nat. Hist., vol. iv, 1851, p. 118. Type, S. elegans Ayres = P. pxilchellus Gray. 
Pentagonaster (Sect. A, a, pars), Perrier, Revision des Stelkrides, 1875, p. 12. 
Aslrogonium , Sladen, Challenger Asteroidea, 1889, pp. 263, 285. 
Stephanaster, Perrier, Exp. Trav. and Talisman, 1894, p. 402. (This is antedated 11 years by Pentagonaster.) 
Pentagonaster, Verrill, Trans. Conn. Acad., vol. x, 1899, pp. 147, 157. 
