STARFISHES OF THE PHILIPPINE SEAS. 279 



of angle being the slenderest, somewhat prismatic and compressed. 

 On the adoral end of the series are usually 2 flattened, roimd-tipped 

 spines, the side to furrow, and on the aboral end 3 or 4 similar 

 but larger ones. The aboral facet of the angle is hollowed out to 

 accommodate the tube foot. Proximally the plates bear 2 or 3 

 series of tubercular granules (7 to 9 in number) ; farther along ray 

 where the angle is prominent there are about 15 in three irregular 

 series parallel to margin. On the outer attenuate part of ray a 

 granule spaced from the rest and sometimes slightly enlarged is 

 found just back of the apex of the angle. No pedicellariae. Sutures 

 between the plates unusually deep. 



Mouth plates with a straight furrow series of 9 or 10 spines like 

 the adambulacrals except that the inner three become gradually en- 

 larged and more compressed. Suboral granules 8 or 9, following 

 the other margins of each plate, the inner 2 or 3 of the series adjacent 

 to median suture being enlarged into short, stout wedge-shaped spines. 



It is noticeable that the ventral plates have more distinct spaces or 

 sutures between them than have those of either euryplax or rrtoluc- 

 canus. 



Madreporic body subpentagonal, surrounded by 4 large plates, of 

 which the largest, on the adcentral side, is the primary basal. The 

 madreporite is a trifle smaller than the primary basals of the other 

 4 interradii, and is situated about one -third the distance between 

 center and inner edge of superomarginals. 



Young. — Two small specimens doubtfully referable to this species 

 have less tumid marginals, broader rays, with the median abactinal 

 depression less pronounced than in the adult. Oral spines 9 ; furrow 

 spines at first 5 increasing to 9. 



Type.— Cat. No. 30547, U.S.N.M. 



Type-Iocalif 7/. —Station 5648, Buton Strait, Celebes (lat. 5° 35' S.; 

 long. 122° 20' E.), 559 fathoms, bottom temperature 39.2° F.; 1 speci- 

 men. 



Distribution. — Celebes. 



Specimens examined. — Three; the type and 2 young specimens 

 doubtfully referred to this species from station 5651, Gulf of Boni, 

 Celebes, 700 fathoms, green mud, bottom temperature 38.7° F. 



Bcmar/cs. — This species differs from ^V. euryplax in having nar- 

 rower rays, tumid marginals, narrower and longer inferomarginals, 

 radial abactinal plates which are not conspicuously wider than long, 

 and 9 or 10 oral spines. In arthrocnemis the plates are more distinct, 

 the granulation coarser, the primary basal plates larger, the madre- 

 poric body surrounded by 4 (not 6) plates, and the dorsal surface of 

 ray is marked by a shallow sulcus, of which the dorsal facets of the 

 superomarginals form the sides. From N. moluccanus, arthrocnemis 



