128 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



culate pedicellariae ; furrow spines 6 or 7, rather long, slender, com- 

 pressed ; subambulacral spines 8 to 12, slender and short. Rays long, 

 of medium width, thin and with an attenuate extremity. R=95 

 mm., r=20 mm., R=4.75 r; breadth of ray at base, 22 nun.; breadth 

 at two-thirds r, 8 mm. 



Description. — Rays, slightly variable in width, but of medium 

 breadth, appressed, the marginal plates forming a thin edge. The 

 superomarginals do not encroach much upon paxillar area and in 

 consequence the latter is broad. Abactinal integument rather thin 

 and flexible, and the paxillae in consequence of tlie upright position 

 of their spinelets, appear spaced. Arrangement of paxillae typical 

 of Persephonaster. Paxillae largest on interradial regions and adja- 

 cent portions of the base of ray where they are of medium size, and 

 consist of 15 to 20 terete pointed spinelets longer than the rather low 

 pedicel. In the center of the disk the paxillae are very slender, with 

 8 or 10 spinelets, the pedicel being longer, shorter, or equal to them 

 in length. Many paxillae have a fasciculate pedicellaria of slightly 

 thickened spinelets. 



Abactinal plates irregularly elliptical on papular areas and more 

 I'oundish on median radial line. Plates of the transverse series touch 

 each other or even overlap slightly but consecutive series are spaced. 

 Many of the plates of the outer half of ray are shaped like an open 

 fan, and the transverse rows are little or not at all interrupted on 

 the radial line. Papulae absent from small area at center of disk and 

 along a narrow radial band. 



Superomarginals, 40 in number, are quite small and form a nar- 

 row border to paxillar area, the inferomarginals extending laterally 

 beyond them and forming a scalloped margin to the ray. In the 

 interbrachial angle the plates are wider than long, then they become 

 square, and beyond the first third of the ray the length gradually in- 

 creases over the width, as the plates become smaller and smaller. 

 The plates are tumid, the apex of the tumidity bearing a short, coni- 

 cal spine and moving from the middle of the plate (at base of ray) 

 to a little distad of the middle. On the outer fourth of the ray the 

 plates are not tumid, and have 2 or 3 spines in a transverse series. 

 The plates are covered with a fine nap of very delicate spinelets. be- 

 coming appressed around the base of the spine and most of them 

 have 1 or 2 small fasciculate pedicellariae near the inner edge. Ter- 

 minal plate very slender, subcylindrical, round-tipped, with a stout 

 terminal spine and 2 or 3 smaller ones on either side. 



Inferomarginals on first third of ray equal in width to 1.5 the 

 length ; at middle of ray the width only slightly exceeds the length. 

 From this point the ray becomes rapidly very attenuate, and the 

 plates are longer than wide. Most of the width of plate is occu- 

 pied by the actinalface. the lateral facet being low, not half as wide 



