312 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



.1 



Actinal intermediate plates 4- or 5-sided, in 5 chevrons, the 

 plates reaching to fourth inferomarginal, and isolated plates reach- 

 ing to sixth. The plates are separated by shallow grooves and bor- 

 dered by a single series of small subconical or acorn-shaped granules, 

 considerably larger than those bordering the inferomarginals, the 

 surface of plate carrying 1 to 5 larger, unequal, acorn-shaped or sub- 

 globose scattered granules. A few of the plates adjacent to furrow 

 have a spatulate sugar-tongs pedicellaria, which is gTiarded by 1 or 2 

 granules, and the broadly spatulate denticulate jaws are dark brown 

 at the tip. -^ 



Adambulacral plates considerably wider than long proximally, 

 gradually narrowing until they are as wide as long, or sometimes 

 on outer part of the ray longer than wide. Furrow spines 4 or 5, 

 very strongly compressed and broad at the tip, which is roundly 

 truncate, the edge being toward furrow. Spaced from these is a 

 longitudinal series of 2 heavy, though proximally slightly shorter, 

 clavate, blunt spines with sometimes a third smaller granuliform 

 member at the proximal end of series. These spines are sometimes 

 irregularly grooved, on the proximal plates. On the outer part of the 

 ray the furrow spines become shorter, and the subambulacral spines 

 are reduced to a single, heavy, tubercular, blunt, slightly tapering 

 spine, longer than the furrow spines. The outer two-thirds of the 

 plate is bordered by granules similar to those of the actinal inter- 

 mediate plates, with 2 or 3 slightly larger acorn-shaped granules 

 on the surface. A few of the proximal plates have, between the 2 

 subambulacral spines, a pedicellaria with 2 rather narrowly spatulate 

 jaws nearly or quite as long as the spines and opening on the trans- 

 verse axis of the plate. The inside of the jaw is concave. 



Mouth plates slightly convex actinally with 9 or 10 strongly com- 

 pressed furrow spines, the innermost very thin and broad at the 

 tip, and sometimes concave on one side so as to appear scoop-shaped. 

 Corresponding to the subambulacrals are 3 suborals, the outer part 

 of the plate being margined by 8 or 9 granules. 



Madrcporic body shield-shaped, surrounded by 5 plates of which 

 3 are larger than itself. It is situated about one-fourth r from center. 

 Striations fine, ridges coarse, interrupted. 



Color in alcohol, bleached yellowish. 



Gonads in a single tuft on either side of the interbrachial septum. 



Type.—C2it. No. 30555, U.S.N.M. 



Type-locality. — Station 5523, 6.7 miles northeast of Point Tagolo, 

 northern Mindanao; depth and bottom not recorded; 1 specimen. 



Distribution. — Known only from the type-locality. 



Remarhs. — This form is closely related to A. callimorphus Fisher, 

 from 127 fathoms, between Maui and Molokai, Hawaiian Islands. 

 The most obvious difference is in the adambulacral armature, the 



