136 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



ra}' and slightly longer distally. Subambulacral spinules 10 to 12, 

 very slender, terete, pointed, in 3 irregular longitudinal series or in 

 1 series of 5 near furrow, and the others without very definite order, 

 the size grading from those of first series, which are nearly as long 

 as the furrow spines, to the outer, which are subequal to the actinal 

 intermediate spinelets. Some of the proximal plates have fasciculate 

 pedicellariae with 3 to 5 shortened, sharp spiniform jaws. The first 

 plate is not very markedly compressed and has a furrow series of 6. 



Mouth plates rather narrow but very convex. The oblique vertical 

 angular series of marginal spines forms a fasciculate group of about 

 5, the outer limb of the angle being continued along the margin 

 adjacent to first tube foot by 3 to 5 additional slender spinelets, in 

 a fan, and thence along the lateral sutural margin, by 7 or 8 delicate 

 spinelets. The inner tooth is stout, fusiform, blunt, or pointed, about 

 half as long as plate. The suboral armature includes a series of 

 8 or 9 short, rather thick, spines along margin of median suture, the 

 innermost two-thirds as long as the tooth, the others rapidly decreas- 

 ing in length. There is also an intermediate series of 6 to 8, subequal 

 to the adjacent superficial spinelets, but not very regular in size or 

 shape. 



Madreporic body a little more than its own diameter from margin, 

 the ridges with small spiniform protuberances. 



Type.—C^t. No. 30528, U.S.N.M. 



2'ype-locality. — Station 5606, Gulf of Tomini, Celebes, 83-1: fath- 

 oms, green mud; 1 specimen. 



Distribution. — Known only from type-locality. 



RemarJcs. — P. monostoechus may be readily distinguished from 

 any of the preceding species by the presence of the erect lateral 

 inferomarginal spine, and by the single series of erect superomar- 

 ginal spines which are at first dorsal in position and gradually move 

 away from the upper edge of the plate and become lateral on the 

 outer part of the ray. The superomarginals are formed very much 

 like those of multicinctus, but the position of the spine, as well as 

 the inferomarginal armature, will at once distinguish moiiostoechus. 



Persejyihonaster croceus Alcock and Wood-Mason is from the Guli 

 of Manaar, 73 8 fathoms. 



■ Genus TRITONASTER Fisher. 



Tritonaster Fishek, 1906, p. 1017. Type, T. craspedotus Fisher. 



TRITONASTER EVORUS Fisher. 



Plate 29, figs. 1, 4 ; plate 30, fig. 6 ; plate 39, figs. 3, 3a-h. 

 Tritonaster evorus Fisher, 1913a, p. G21. 



Diagnosis. — Eays 5. R=31 mm., r=7 mm., R=4.4 r: breadth of 

 ray at base, 7.5 mm. Eays pointed, fairly stout, very evenly tapering 

 from narrow base; interbrachia abruptl}'' rounded, abactinal integu- 



