STARFISHES OF THE PHILIPPINE SEAS. 285 



Station 5423, Sulu Sea near Cagayanes Islands, 508 fathoms, gray 

 mud, coral sand ; bottom temperature, 49.8° F. ; 1 specimen. 



Station 5424, same locality, 340 fathoms, coral sand; bottom tem- 

 perature, 50.4° F. ; 2 specimens. 



Remarks. — This species differs from eiiryplax and moluccanus in 

 having narrower rays, which are arched proximally; in having the 

 superomarginals extending laterally farther than the inferomar- 

 ginals, not the reverse; from eiiryplax further in having more nu- 

 merous oral spines, more numerous furrow spines, and radial plates 

 not conspicuously widened; from moluccanus also in having nar- 

 rower superomarginals and marginal pedicellariae; from arthro- 

 cnerrds in lacking swollen marginals and the characteristic depres- 

 sion along the ray, in having plane not tumid actinal intermediate 

 plates, more numerous oral and furrow spines, finer granules, mar- 

 ginal and adambulacral pedicellariae; from atopus in having 6 

 (young) to 10 interbrachial superomarginals (not 4), numerous 

 pedicellariae, larger, slightly elevated abactinal plates, more numer- 

 ous mouth spines, and stouter inferomarginal plates. The characters 

 which separate this form from meseres are noted under that species. 



NYMPHASTER ATOPUS Fisher. 



Plate 63, fig. 4; plate 64, fig. 2; plate 69, fig. 5; plate 70, fig. 4; plate 92, 



figs. 7, la. 



Nymphaster atopus, Fisher, IdlSa, p. 640. 



Diagnosis. — Differing from other species herein described in having 

 only 4 interbrachial superomarginals ; rays slender, the width at outer 

 end of second superomarginals (which corresponds in position to the 

 inner end of the first pair of plates which meet medially, in other 

 species) equaling length of first 3 superomarginals measured on am- 

 bitus; superomarginals longer than wide; inferomarginals on ray 

 very slender, resembling terete rods placed end to end; marginal 

 granulation relatively coarse, spaced; abactinal plates small, round- 

 ish hexagonal, with few granules; oral spines 9 or 10; adambulacral 

 furrow spines proximally 7 or 8, then 10 or 11 ; apophysis is promi- 

 nent from the third plate on; distal plates much longer than wide, 

 with 1 series of granules and a few extra in the angle of the apophy- 

 sis; about 15 or 16 adambulacrals corresponding to 10 inferomargi- 

 nals of ray. Cotype, E=43-)-mm., r=9 mm., R=at least 5 r (tip of 

 ray broken). 



Description. — Abactinal area, within the marginal plates, pentago- 

 nal and bounded on each side by 4 superomarginals. Abactinal 

 plates small, slightly convex, the papular areas comprising 5 longi- 

 tudinal series of roundish hexagonal plates and the interradial areas, 

 abour 4 chevrons of still smaller roundish or irregularly polygonal 

 ones. Radial plates with 1 central and 6 or 7 peripheral subspherical 



