638 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 43. 



Type-locality. — Station 5622, between Gillolo and Makyan 

 Islands, Molucca Islands, 275 fathoms, gray mud. 



The petaloid papular areas are narrower than in euryplax, compris- 

 ing 7 to 9 longitudinal series of plates. Proximal median radial 

 plates with 8 to 10 circular, depressed, central granules (in 3 trans- 

 verse series) and 15 or 16 slightly smaller, peripheral ones. Supero- 

 marginal plates broad, very famtly convex, and with an abrupt 

 rounded angle at ambitus. They form a slightly raised border to 

 disk, and one which is a trifle on a bevel ; fifth superomarginals the 

 largest, meeting medially. Superomargmal granules depressed, 

 hemispherical, slightly larger than on neighboring abactinal plates, 

 slightly spaced, with a regular beadUke marginal series. The 

 apophysis or furrow angle of adambulacral plates begins on fourth or 

 fifth plate and rapidly increases in prominence, the adoral facet of the 

 apophysis being about two-tliirds the length of the aboral, which is 

 shghtly hollowed out. The subambulacrtil granules are 15 to 25 in 3, 

 sometimes 4, irregular rows; outer granules hemispherical, becoming 

 somewhat four-sided or prismatic toward the furrow, and on the disk 

 the innermost series is enlarged into short tubercular subprismatic 

 spines, winch decrease in length as the base of ray is approached. On 

 the disk a few plates have a small pedicellaria, with 3 slender curved 

 jaws, in the inner series of subambulacral spines, opposite the furrow 

 angle. 



This species differs from N. ludwigi (Kceliler) in having broader rays 

 at the base, which taper more abruptly ; more numerous marginals in 

 each interbrachium ; wider adambulacrals with 3 or 4 rows of granules 

 instead of 2; a much more prominent apophysis proximally on the 

 adambulacral plates; a few adambulacral and actinal intermediate 

 but no marginal nor abactinal pedicellarise ; madreporic body sur- 

 rounded by 5 or 6 plates instead of 4. 



NYMPHASTER ARTHROCNEMIS, new species. 



In the form of the marginal plates resembling N. ternalis (Perrier) 

 but with smaller disk, longer rays, smaller radial abactinal plates, 

 smaller papular areas; furrow angle of adambulacrals beginning with 

 the third or fourth instead of the twenty-fourth plate; no adambu- 

 lacral and marginal pedicellarise. Marginal plates tumid, the median 

 line of ray depressed below the lateral angle of superomarguials ; 

 ray rather slender from the base, the w^dth 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 adambulacrals with at first 7 fur- 

 row spines and at middle of ray 9 to 11, usually 10; actinal granu- 

 lation coarse; no i3edicellariae except on abactinal plates. R. = 85 + 



