450 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



decrease in size to about 0.75 mm. on the dorsal side of the paxilla. 

 The proximal siiperomarginals have 12 to 15 spines and the pedicel 

 is about two-thirds the height of the inferomarginal pedicels, while 

 the tuft of spines is of about half the bulk of the inferomarginal 

 spines. Actinal interradial areas small, the plates bearing 3 or 4 

 spinelets and extending in a single series about two-thirds the 

 length of ray. 



Furrow spines 5 or 6, usually 6, slender, tapering, webbed for two- 

 thirds their length, the 4 median the longest, and about 1^ times the 

 length of base line of comb. Consecutive combs are separated by an 

 interval equal to one-half to the entire length of the base line comb. 

 Subambulacral spines 3 or 4, tapering, pointed, the outermost com- 

 monly the longest, or the 2 or 3 outermost subequal and about twice 

 as long as the median furrow spines, as well as much stouter, the end 

 of the spines being sometimes a trifle swollen. They are united by 

 web at the base only. 



Marginal mouth spines 12 or 13, webbed, and increasing in length 

 toward the innermost. Suboral spines, 2 to 4 on the median suture 

 margin near outer end of plate. 



Madreporic body prominent, situated at about the middle of r. 



Type.— Co^t. No. 32646, U.S.N.M. 



Type-locality. — Station 5423, Sulu Sea, off Cagayan Island, 508 

 fathoms, gray mud, coral sand; bottom temperature 49.8° F. ; 1 

 specimen. 



Remarks. — This species is characterized, so far as the single speci- 

 men allows one to judge, by the very low pedicels and relatively 

 long spines. The marginal paxillae are small, but the subambulacral 

 spines are unusually large. L. suluensis differs from L. furcifer in 

 having longer, slenderer rays, longer paxillar spines, and relatively 

 shorter pedicels, longer and unequal marginal paxillar spines, more 

 numerous furrow spines, and very much longer subambulacral spines, 

 the latter being longer than the marginal paxillae with their spines. 

 The mouth plates of L. suluensis are larger, with more numerous and 

 longer marginal spines (12 or 13). L. suluensis differs from L. 

 stella.ns Sladen, and L. ahhreviatus Koehler (Antarctic species) in 

 having a much less robust form, longer rays, more numerous furrow 

 spines (4 short ones in stellans and 3 rather long ones in ahhreviatus) 

 and much more prominent subambulacral spines (longer, not shorter, 

 than marginal paxillae with their spines). L. suluensis resembles, 

 in general form, more nearly 2 Antarctic species: L. antarcticus 

 Koehler and L. gaini Koehler, but differs in having 5 or 6 instead of 

 4 furroAV spines, and 12 or 13 instead of 7 or 8 marginal mouth 

 spines. L. antarcticus has 20 to 40 paxillar spines and much less 

 prominent subambulacral spines Avhen compared either with the 

 fairly long furrow spines or the more prominent inferomarginal 



