NO. 1944. NEW GENERA AND SPECIES OF STARFISHES— FISHER. 603 



Type.— Cut. No. 30507, U.S.N.M.* 



Type-locality. — Station 5123, east coast of Mindoro, Philippine 

 Islands, 220 to 283 fathoms, green mud. 



PRIONASTER GRACILIS, new species. 



Differs from Prionaster analogus in having conspicuously longer 

 rays, with a distally wider paxillar area which reaches terminal plate; 

 paxiUse with slenderer, sharper spinelets; superomarginals narrower 

 abactinally; cribriform organs open and exposed proximally; longer 

 marginal spines; more numerous adambulacral spinelets; first adam- 

 bulacral not compressed; double series of interradial actinal plates 

 wider at inner or central end; enlarged subambulacral on middle 

 portion of ray only. R, = 165 mm., r = 24 mm., 11 = 6.9 r; breadth 

 of ray at base, 24 mm., at tenth inferomarginal, 14 mm. Paxillse 

 small and crowded. Superomarginals 74, the distals about as wide 

 as liigh (much wider than high in analogus) . Cribriform organs much 

 more open than in analogus and more as in Ooniopecten asiaticus. In 

 interbrachium the width of the exposed portion of organ (exclusive 

 of marginal web) is a Httle over one-third height of superomarginal, 

 or one-haH lateral face of inferomarginal. Adambulacral plates 

 angular as in analogus, but in midregion of ray not so strongly so and 

 ^vith 12 to 14 furrow spines, webbed for nearly half their length, the 

 median spinelets sUghtly the longest. Four or 5 shorter spinelets on 

 outer border of plate, immersed in membrane, one of them becoming 

 a specialized subambulacral on the midregion of ray; not enlarged 

 on distal or proximal part of ray. 



Type.— C&t. No. 30508, U.S.N.M. 



Type-locality.— ^ts^iion 5425, Sulu Sea (lat. 9° 37' 45" N.; long. 

 121° 11' E.), 495 fathoms, gray mud, coral sand; bottom tempera- 

 tm-e, 49.4° F. 



PRIONASTER MEGALOPLAX, new species. 



Differing from Prionaster analogus in the following features : Large 

 compact paxillse mth very numerous spinelets; large madreporic 

 body; superomarginals not in contact distally; superomarginal spines 

 absent or rudimentary; more open cribriform organs; relatively 

 larger mferomarginal spines; the odd interradial double series of 

 actinal intermediate plates broader at inner end and with more plates; 

 first adambulacral not markedly compressed; more numerous fur- 

 row spines. E, = 250 mm., r = 50 mm., R = 5 r; breadth of ray at base, 

 56 mm., at tenth superomarginal, 28 mm., at middle of ray, 20 mm. 

 Paxillse closely crowded, with stout pedicels, bearing each a fiat- 

 topped polygonal group of equal terete, blunt spinelets, about 25 to 

 30 occupying the periphery, and 20 to 40 the center. Supero- 

 marginals 74, the special spinule being either absent, or present as a 

 small spinelet on the proximal half of ray. Inferomarginal spine 



