STARFISHES OF THE PHILIPPINE SEAS. 133 



of 8 to 12 spinules. The first plate is compressed and has an angular 

 furrow series of 5, and 2 transverse subambulacral series of about 8 

 or 9 spines. No subambulacral pedicellariae. 



Mouth spines fewer than in oediplax. Laterally from the base of 

 the compressed tooth, and directed into mouth of furrow is a fasci- 

 culate group of 4 or 5 small pointed tapering spinelets resembling 

 and probably functioning as a pedicellaria. This is the usual Perse- 

 phonaster group of spines belonging to the marginal series. It is 

 continued on the margin of plate facing the furrow by about 3 

 longer, bluntly pointed spines, and thence along the lateral suture 

 margin by 5 or 6 additional shorter slender spinelets. The super- 

 ficial series, along edge of median suture, consists of about 8 promi- 

 nent, flattened, slender or lanceolate blunt spinules decreasing in 

 length toward outer end of plate. The mouth plates are much nar- 

 rower than in oediplax^ or any other of the preceding species, and 

 are notable for their small size generally. The distance between the 

 superficial and marginal series of spines is slight. 



Madreporic body small with coarse striae and a paxilla on the 

 .surface adjacent to the adcentral margin. It is situated about two- 

 thirds r from center. 



Type.— C^i. No. 30527, U.S.N.M. 



Type-locality. — Station 5114, Verde Island Passage, vicinity of 

 Balayan Bay, southern Luzon 340 fathoms, fine sand ; 2 specimens. 



Distribution. — Balayan Bay, Luzon, and Sibuko Bay, Borneo, 305 

 to 340 fathoms. 



Specimens examined. — Three, the types and 1 from 5592, Sibuko 

 Bay, Borneo (lat. 4° 12' 44'' ^.; long. 118° 27' 44" E.), 305 fathoms, 

 green mud, bottom temperature 43.3° F. 



Remarks. — This species is an aberrant Perseplionaster in that its 

 marginal and mouth plates are distinctly smaller than the mean for 

 the genus, and the general habit is slender and light. The actinal 

 interradial areas are also small, and the furrow spines of the adam- 

 bulacral plates reach the lowest number known in the genus. P. 

 hahrogenys agrees with P. gracilis (Sladen) in having small mouth 

 plates, but differs in possessing armed superomarginals, smaller disk, 

 higher paxillae; in having the lateral and ventral facets of the in- 

 feromarginals better differentiated, and the long inferomarginal 

 plates lateral in position; in having fewer furrow spines. The 

 marginal plates of gracilis are much less tumid than those of 

 hahrogenys. Dy taster anacanthus Alcock and Wood-Mason (Bay of 

 Bengal, 1,748 fathoms) is certainly not a Dytaster. Although the 

 mouth plates are imperfectly described, the species, as Alcock states, 

 seems to be near P. gracilis (Sladen) and for that reason, if for no 

 other, probably should occupy a niche in the genus Persephonaster. 

 It has unarmed superomarginals which are more lateral in position 

 13434— Bull. 100—19 10 



