500 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



ray. The plates each bear a short, somewhat four-sided, only 

 slightly tapered, spinelet, superficially truncate, but really terminat- 

 ing in 3 or 4 minute sharp prongs, with sometimes accessory points 

 below them. These spinelets are 0.4 to 0.6 mm. in length and 0.15 

 to 0.18 mm. thick just above the base. These spinelets are borne on 

 a slight rounded eminence at the middle of the plate. A few abacti- 

 nal plates have a smaller accessory spinule on one of the lobes. 

 Each plate bears also 1 to 4 forcipiform, ovoid pedicellariae, usually 

 on the margin of the papular areas, and about 0.36 to 0.38 mm. in 

 length. These have the appearance in the dry specimen of being 

 pretty uniformly scattered over the surface of the body. 



There are 8 longitudinal rows of somewhat quadrate papular areas, 

 which usually contain a single papula. In addition between the 

 first and second actinal intermediate series of plates is a very short 

 series of narrow subtriangular papular areas. 



The terminal plate is large and subcircular except on the side 

 toward the ray, where there is an obtuse angular notch or indentation. 

 The plate is covered with spinelets 2 or 3 times as long as those of the 

 adjacent abactinal and marginal plates. 



Adambulacral armature, a regular transverse series of 3 slender, 

 tapering pointed, slightly thorny spinlets, the median a trifle the 

 largest, borne on a moderately developed ridge of the plate. On the 

 outer two-thirds of the ray there are only 2 such spines. About 6 or 8 

 plates along either side of each furrow, and irregularly spaced, bear 

 on the inner edge, near the furrow spine, a relatively huge unguicu- 

 late forficiform pedicellaria, with usually three curved claws or 

 teeth. These are 1 to 1.2 mm. long and resemble 2 minute clasped 

 hands (with 3 short fingers). On 2 rays there is a large pedicellaria 

 on the outer side of the third plate. Most of the adambulacral plates 

 have also an ordinary forcipiform pedicellaria just external to the 

 outermost spine. 



Mouth plates fairly prominent and with a prominent median 

 suture. The form of the combined pair is a truncated oval, the sub- 

 oral surface being narrower toward the inner than at the outer end. 

 Armature: a single series of tapered spinules, there being usually 3 

 larger ones on the actinal surface and 2 conspicuously smaller ones, 

 one above the other, on the actinostomial face of the plate. One plate 

 has a large cat-claw pedicellaria on the outer, furrow corner. 



Tube feet strictly biserial. Madreporic body flat, with radiating 

 coarse striae. It is situated about midway along the minor radius. 



Type.— C^t. No. 37030, U.S.N.M. 



Type-locality.—Station 5656, Gulf of Boni, Celebes (lat. 3° 17' 

 40'' S.; long. 120° 36' 45" E.), 484 fathoms, gi-ay mud, bottom tem- 

 perature 41.2° F. ; 1 specimen. 



