STARFISHES OF THE PHILIPPINE SEAS. 277 



verticals") apparent on the third plate. This specimen has nar- 

 rower rays than moluccanus^ larger radial plates, with more numer- 

 ous granules. It is probably not true ternclis. Among the species 

 figured by Perrier (1894) moluccanus most nearly resembles in gen- 

 eral appearance N. arenatus^ but the marginals are not so wide in 

 proportion to length, there being fewer in each interbrachium than 

 in arenatus; oral spines more numerous (9 in arenatus) ; furrow 

 spines more numerous (7 in arenatus) ; subambulacral granules much 

 more numerous. The form of the radial plates will separate moluc- 

 canus from belli. 



NYMPHASTER ARTHROCNEMIS Fisher. 



Plate 64, fig. 1; plate 65, fig. 4; plate 68, fig. 1; plate 69, fig. 1; plate 92, 



figs. 9, 9a-6. 



Nymphaster artlirocnemis Fisher, 1913a, p. 638. 



Diagnosis. — In the form of the marginal plates resembling N. ter- 

 nalis^ (Perrier) but with smaller disk, longer rays, smaller radial 

 abactinal plates, smaller papular areas; furrow angle of adambula- 

 crals beginning with the third or fourth instead of the twenty-fourth 

 plate; no adambulacral and marginal pedicellariae. Marginal 

 plates tumid, the median line of ray depressed below the lateral angle 

 of superomarginals; ray rather slender from the base, the width at 

 inner end of first pair of superomarginals which meet medially 

 equaling length of first 4 superomarginals (or a trifle less) ; radial 

 plates hexagonal; mouth plates with 9 marginal spines and adam- 

 bulacrals with at first 7 furrow spines and at middle of ray 9 to 11, 

 usually 10; actinal granulation coarse; no pedicellariae except on 

 abactinal plates. R=85-[-mm., r=21 mm., R=over 4 r (small por- 

 tion of tip of ray broken) ; breadth of ray at midinterbrachium, 

 24 mm. 



Description. — Abactinal area, inside the marginal plates, nearly 

 pentagonal and slightly produced at corners. Abactinal plates very 

 regularly arranged, the papular areas comprising 6 or 7 rows of 

 roundish hexagonal plates and the triangular interradial areas about 

 7 chevrons of squarish or polygonal ones; or parallel with the me- 

 dian radial series are on either side about 9 series, of which usually 

 3 belong to the papular area ; basal or interradial plates conspicuous, 

 slightly larger than madreporic body, and containing about 36 gran- 

 ules. The larger median radial plates have 10 to 12 central and 

 about 12 to 15 peripheral, subcircular (sometimes subpolygonal), flat- 

 topped or slightly convex granules. The adradial plates have com- 

 monly 5 to 10 central granules. These granules are not crowded, 

 and a slight space occurs between the central group and the pe- 



» Perrier, 1884, pi. 10, fig. 1. 

 13434— Bull. 100—19 19 



