THE STAKFISHES OF THE HAWAIIAN ISLANDS. 
1003 
ee. Skeleton reticulated. Adambulacral plates not dimorphic. Adambulacral plates with 1 
or 2 spines. Pedicellarise usually numerous, either in wreaths about the spines, or 
scattered Asteriidte 
c c. Tube-feet in 2 series throughout the ray. Actinostome with adambulacral plates prominent. 
Rays numerous, always more than 5, slender, sharply defined from disk, and armed with 
slender spines which are sheathed in membraneous sacculi bearing many minute crossed 
(forcipiform), pedicellarise. Abactinal skeleton confined to disk and base of ray, on the 
latter often disposed in independent spaced annular ridges or costae Brisingid.e 
Order PHANEROZONIA Sladen, emended. 
Family ASTROPECTINIDA Gray, 1840. 
Astropectinidae Gray, Synopsis of the Genera and Species of the Class Hypostoma ( Asterias Linn.) <Ann. N. H., ser. 1, vol. 
VI, 1840, p. 180. 
Key to the Hawaiian genera of Astropectinidse. 
a. Both series of marginal plates well developed, forming a nearly vertical lateral face to ray. 
Superomarginal plates are not confined to the abactinal surface beyond basal fourth of ray, but 
form a part of the side wall of ray. 
b. Inferomarginal plates separated from adambulacral plates throughout a portion of the ray by a 
series of small intermediate plates. Fasciolar grooves not well developed. 
c. Marginal plates not tumid; intermediate plates extending nearly to tip of ray Psilaster 
cc. Marginal plates strongly tumid; intermediate plates extending only one-third length of 
ray Psilasteropsis 
bb. Inferomarginal plates touching adambulacrals; not separated throughout ray by a row of inter- 
mediate plates. Fasciolar grooves specialized, well developed Astropecten 
aa. The 2 series of marginal plates very unequal in size, forming an angulated margin to ray. Upper 
series much smaller, and usually confined to abactinal surface; lower series extending laterally 
beyond superior series. 
b. Madreporic body not large and hidden by special paxillse on its surface. Anal aperture very 
minute or wanting. 
c. No well developed series of plates between inferomarginal and adambulacral series throughout 
ray (rudimentary at base of ray in dd.) 
d. Size large. Rays long; a lateral series of flat, leaf-like spines bordering ray; superomarginal 
plates not conspicuously smaller beyond middle of ray Astropecten 
dd. Size small. Oblique series of long seta-like spines on each tumid inferomarginal. Supero- 
marginals very much reduced in size on outer half of ray Tritonaster 
cc. A well developed series of actinal intermediate plates between inferomarginals and adambula- 
crals. Inferomarginal plates broad and short, band-like; their spines many, appressed to 
ray Ctenophoraster 
bb. Madreporic body large, hidden by paxillse. Anal aperture present, conspicuous in Dipsacaster. 
Fasciolar grooves very deep. 
c. Gonads disposed in a series along either side of abactinal integument of ray, extending beyond 
'middle; papulae distributed generally over the paxillar area Dipsacaster 
cc. Gonads confined to interradial regions, not extending far along rays; papulae confined to the 
sides of paxillar area; absent from central portion of disk and rays Patagiaster 
Genus ASTROPECTEN Schulze. 
Astropecten C. F. Schulze, Betraehtung der versteinerten Seesterne u. ihrer Theile. Warschau u. Dresden, 1760. 
Key to Hawaiian Species of Astropecten. 
a. Superomarginal plates with a single series of erect spines. 
b. Spines stout, absent from second and sometimes third superomarginal. Spines of inferomarginals 
very prominent; not delicate, nor in an oblique comb polyacanthus 
