STARFISHES OF THE PHILIPPINE SEAS. 451 



paxillae. L. gaini has more prominent paxillar pedicels, less thorny 

 paxillar spines, more prominent inferomarginal paxillae, and the 

 actinal intermediate paxillae are reduced to about 4 in each inter- 

 radial area. In L. suluensis they extend at least two-thirds the length 

 of the ray. 



Genus XENORIAS Fisher. 



Xenorius (subgenus) Fisher, 1913c, p. 222. Type, RMpidaster (Xcnorias) 

 polyctenius Fisher. 



Diagnosis. — Differing from Rhipidaster Sladen in the position of 

 the marginal plates which are oblique, but instead of being parallel 

 with one another are inclined at an angle of 45° and touch by the 

 intermarginal ends, forming a series of chevrons along the side of 

 ray. Abactinal plates and adambulacral plates essentially as in 

 Rhipidaster. 



XENORIAS POLYCTENIUS (Fisher). 



Plate 120, fig. 1 ; plate 123, fig. 1 ; plate 133, figs. 1, la-h. 

 Rhipidaster {Xenorias) polyctenius Fishek, 1913c, p. 222. 



Diagnosis. — Rays 7; R=50 mm., r=14 mm., R=3.5+r; breadth of 

 ray at base, 12 mm. ; rays slightly convex, tapering evenly to bluntly 

 pointed extremity. Differing from Rhipidaster vannipes in having 

 very much shorter abactinal spinelets invested in a common sheath ; 

 curiously compressed, obliquely oriented, lateral superomarginal 

 and inferomarginal plates (with intermarginal ends adorad) bear- 

 ing a transverse comb of webbed spines, those at the aboral end of 

 each plate much larger than the others; furrow spines 9 or 10; sub- 

 ambulacral comb of 4; abactinal integument pulpy, hiding the 

 skeleton which consists of 3 or 4 lobed closely imbricated plates; 

 papulae 1 to 3 to each mesh. 



Description. — Abactinal surface covered with rather uniformly 

 distributed fascicular tufts of small spinlets invested in a common 

 pulpy sheath from which the tips of the spinlets protrude a short 

 distance. These fascicles with their investment are about 1 mm. long 

 and 0.75 mm. in diameter, and resemble tubercular projections of the 

 integument. In those which appear to be nearly normal the in- 

 vestment forms a collar surrounding the spinelets which are them- 

 selves embedded in the central pulpy part of the sheath. These 

 fascicles are spaced about once their own diameter, or less, on disk 

 and base of rays, and are arranged in quincunx on the sides of the 

 rays. Each pseudopaxilla consists of a low pedicel or convex plate, 

 surmounted by 8 to 12, or sometimes fewer very delicate tapering 

 glassy spinelets closely bound for their basal half by tissue, and 

 ending in several very sharp glassy points. On the central part of 

 disk and outer part of ray many plates have 5 or 6 spinelets. The 



