1010 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Astropecten productus, new species. 
PI. II, figs. 5, 5a-5f; pi. IV, figs. 1-3. 
Rays 5. R=183 mm.; r=19.5 mm. R=9.3 r. Breadth of ray at base, opposite first supero- 
marginal, 23 mm. ; opposite fifth superomarginal, 25 mm. Width of ray 1 centimeter from tip, 10 
mm. Height of ray at base, 10 mm. 
Size large; rays long, rather slender and flat; disk relatively very small, the minor radius being 
less than the width of ray at base. General form depressed, flat. The rays taper very gently to 
a blunt extremity, and on the outer portion the sides appear almost parallel when viewed from 
above. Most of the rays are constricted at the base, so that the widest portion is at the fourth or fifth 
superomarginal plate. Interbrachial arcs are very acute. Abactinal surface plane; actinal surface 
convex, with broadly beveled margins. 
Abactinal paxillar area is uniform and moderately compact on disk, but often rather open on the 
rays, since the spinelets of the small paxillse frequently do not radiate to any extent. In specimens 
where the paxillse are all expanded like flowers the general appearance is compact. Paxillse are 
arranged in rather regular transverse rows at base of ray, except along the medioradial line. On 
outer half of ray these regular series are confined to a narrow border adjacent to the superomarginal 
plates. No regularity on disk. Each paxilla is surrounded by about 6 papulae in a hexagonal series. 
The latter are absent from the medioradial line of ray. The paxillse are largest on disk and at either 
side of medioradial areas. Each consists of a short cylindrical ossicle, flaring at the base, flat-topped, 
sometimes elliptical in section, surmounted by a central group of 7 or 8 slender spinelets, which are 
surrounded by a marginal row, more or less irregular, of from 12 to 16. On outer third of arm paxillse 
are smaller, but the spinelets decrease only a trifle in number, the average being about 10 in marginal 
series and 4 or 5 in the central group. Scattered among these are still smaller paxillse with 7 or 8 
marginal spinelets and only 2 or 3 central ones. The spinelets are two-thirds as long as the supporting 
pedicel. 
Superomarginal plates, about 90 to 92 in number from interradial line to extremity of ray, form 
a well defined, conspicuous, and uniform border to paxillar area. Except for the first 8 or 10 plates 
they lie entirely on the abactinal surface. The inferomarginals with their prominent spines form the 
edge of the ray as they project laterally beyond the superomarginals. In the interbrachial arcs the 
superomarginals for a short distance form a rounded bevel to the margin. They decrease very 
gradually in size toward the extremity of ray. The length equals about two-thirds the width. 
The plates are set obliquely, as to their transverse vertical axis, so that their aboral margin slightly 
.overlaps the adoral of the succeeding plate. The aboral margin is curved, and is armed with a series 
of 4 (varying to 3, 5, or 6) short, stumpy, sharp, squamiform spinules, evidently modifications of the 
squamiform spinelets which cover remainder of exposed surface of plate. In the fasciolar grooves 
between plates the papilliform spinelets are slender, becoming gradually thicker, then flatter, toward 
the aboral margin. In dried specimens, after the membrane has disappeared, this graduation in size 
is even more evident, but the spinelets no longer appear papilliform, owing to ,the absence of an 
organic investment. On the first 2 superomarginals one of the spinules is enlarged, becoming 
conical and erect, but it is not conspicuous. Terminal plate fairly conspicuous, bifurcate at base, blunt, 
grooved on lower surface. 
Inferomarginals, which correspond in number to superomarginals, are very wide in proportion to 
length (3.5 to 4.5 : 1) and form a broad even bevel to the margin of the actinal area. The upper end 
of each plate extends beyond superomarginals, is strongly tumid, and the series forms the margin of 
the ray. The inner or lower end of the inferomarginals slightly overlaps the outer end of the 
adambulacral plates. Armature of each inferomarginal plate consists of numerous spines of various 
sizes, which may be roughly divided into two series: (1) Along the aboral edge of each plate, 
extending from the extreme inner to the upper or abactinal tumid end, is a row of from 10 to 14 
spines and spinules. The uppermost spine surmounts a slight boss on the abactinal tumid end of the 
plate and is large, flat, leaf-like, lanceolate-acute, or oblanceolate-acuminate, about 6 to 7 mm. in 
length, by 1.5 to 2 mm. broad. These blade-like spines are very conspicuous, and form a regular 
series along the side of the ray, resting with their flat side upward. Following these, on the very 
edge of the ray, are 2 sharp, slender, slightly flattened spines, the upper usually the longer, being 
about two-thirds to seven-eighths as long as the heavy lateral spine. Occasionally there are 3 in the 
