222 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.46. 



SOLASTER SCOTOPHILUS, new species. 



Related to Solaster papposus, but differing in being of a much more 

 delicate habit, with more numerous furrow and suboral spines, 

 smaller paxillas, smaller and more numerous marginal paxillse, and 

 a much more delicate skeleton. Rays 9. R = 48 mm., r=14 mm., 

 R = 3.4 r; breadth of ray at base, 10 mm.; disk large, rays slender, 

 flexible, tapering to a sharp point; skeleton delicate, open, irregular; 

 paxillse small, the pedicel about 0.5 mm. high and the longest spine- 

 lets 1.25 mm. long; marginal paxillse, 24 or 25, delicate; furrow 

 spines very delicate, 8 or 9; subambulacral spines, 7 to 9; marginal 

 mouth spines, 15. 



Type.~Cat. No. 32648, U.S.N.M. 



Tijpe-locality. — Station 5651, Gulf of Boni, Celebes, 700 fathoms, 

 green mud; bottom temperature 38.7° F. 



The only species, besides (S'. papposus, to which S. scotopMlus shows 

 close resemblance are S. penicillatus (Sladen) and S. japonicus Fisher. 

 S. japonicus is of the habit of S. papposus, having large penicillate 

 paxillag, and heavier spines generally than occur in scotopMlus. From 

 S. penicillatus, scotopMlus differs in having much more numerous 

 furrow spines (4 or 5 in penicillatus), more numerous marginal 

 paxillse, and smaller and more delicate abactinal paxillse. 



Genus RHIPIDASTER Sladen. 

 XENORIAS, new subgenus. 



Differing from RMpidaster sensu strictu 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 inter- 

 marginal ends, forming a series of chevrons along the side of ray. 

 Abactinal plates and adambulacral plates essentially as in RMpidaster. 



Type of subgenus. — RMpidaster (Xenorias) polyctenius, new species. 



RmPIDASTER (XENORIAS) POLYCTENIUS, new species. 



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 R. vannipes in having very much shorter 

 abactinal spinelets invested in a common sheath; curiously com- 

 pressed, obliquely oriented, lateral, superomarginal and inferomar- 

 ginal plates (with intermarginal ends adorad) bearing a transverse 

 comb of webbed spines, those at the aborad end of each plate much 

 longer than the others; furrow spines 9 or 10; subambulacral comb of 

 4 spines; abactinal integument pnlpy, hiding the skeleton which con- 

 sists of 3- or 4-lobed, closely imbricated plates ; papulae 1 to 3 to each 

 mesh. 



