102 HULLKTIN "le, UNITED STATES NATIONAL MUSEDM. 



gradually arching inward and upward on outer half, so that marginal plates form a 

 steep bevel; intorbrachial arcs rounded. Ambulacral furrows wiile; tube feet 

 largo and pointed. Paxillsc small, without regular order, with fifteen to twenty 

 short papilliform spinclets on larger ones; certain scattered paxillte with two, 

 three, or four jawed pedicellariaj; papula; absent from terminal 0.4 of ray. Supero- 

 marginal plates fifty, subquach-ate, slightly tumid, bearing a single tapering spine 

 on upper edge, forming a longitudinal series along dorso-lateral margin of ray 

 except verj- end; a similar spine on middle of each inferomarginal, forming a 

 similar series on ventro-lateral border; marginals covered with fine nap-like spinu- 

 lation, increasing in size toward middle of plates, and lower edge of inferomarginals. 

 Adambulacrals long and narrow with ten short furrow spinelets, and about two 

 rows of much shorter ones on actinal surface; distal most plates Avith an enlarged 

 central spine. Actinal interradial areas small, the plates extending to sixth or 

 seventh inferomarginal and covered with spaced spinelets. A few pedicellarise 

 consisting of three or four clavate, curved, often scoop-shaped jaws, evidently 

 modified spinelets, to each interradial area. Madreporic body very large, hidden 

 by about forty large paxillaj. Superambulacral plates present; gonads extending 

 far along ray. 



Description. — Abactinal paxillar area nearly flat on ray, slightly convex on 

 disk, and on outer third of area becoming rapidly very narrow, so that for a con- 

 siderable distance near the extremity only three or four longitudinal rows of small 

 paxillsc separate the supcromarginal plates of either side. Paxillse rather small, 

 without definite order, and rather crowded on disk but distinctly spaced on ray; 

 at base of ray, about four paxillae opposite each supcromarginal. Each paxilla 

 with a pedicel broader at tip than at base, the former being often elliptical when 

 viewed from above; paxUla crown consisting of a nearlj^ flat topped, subcircular 

 or four-cornered group of short, cylindrical, papilliform, obtuse, equal-sized spinelets, 

 or the peripheral slightl}' slenderer. There are fifteen to twenty spinelets to a 

 paxilla at base of rays, even more on disk, and about twelve to fifteen at outer part 

 of raj'. These stand vertically, the peripheral series flaring a trifle on disk and 

 basal portion of rays, but on outer part of ray the peripheral series radiate widely. 

 The paxilla^ are a trifle smaller along midradial line than on either side, and are 

 largest on interradial areas of disk and adjacent portions of the rays. Scattered 

 rather widely over disk and rays, but occurring especially adjacent to superomargi- 

 nals, certain paxillae bear a single two, three, or four jawed pedicellaria. The jaws 

 are verj- much stouter than the spinelets, but do not extend much above their 

 general level, and are curved toward each other, being scoop-shaped at the tips. 

 These pedicellariaj are verj' inconspicuous. Sometimes they replace all the spinelets 

 of a pedicel, but usually there is a more or less interrujited peripheral series sur- 

 rounding them like the calyx of a flower. 



Abactinal plates crowded, often slightly overlapping, subcircular, irregular, 

 or with slight indication of lobing, especially on disk. Papula? small, rather irregular 

 in position, absent from distal 0.4 of ray, and on disk from numerous narrow areas 

 radiating from center. There are usually about four papulae around the paxillae; 

 occasionally five, often onlv three. 



