278 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



ripheral series. The interradial are involved in a thin membrane. 

 The entire graniihition of this species is coarser than in euryplax and 

 moluccanus. A few pLates of the papular areas have a small pedicel- 

 laria with 2 broadly spatulate, almost truncate jaws. 



Superomarginals 33+, tumid, with an oblique abactinal surface 

 on disk, and a low lateral face; but beyond the fifth, which meets its 

 fellow medially, the dorsal surface slopes inward toward the suture 

 between the 2 opposite series and the lateral face is about half as 

 high as width of abactinal. The angle between the 2 facets is less 

 than a right angle, and the edge is slightly tumid and evenly rounded. 

 Also on the side of the ray the suture between the 2 scries is in the 

 bottom of a broad trough, the sloping sides of which are formed by 

 the lateral facets of the 2 series. The superomarginals on disk 

 extend laterally slightly beyond inferomarginals, and the dorsal sur- 

 face of the plates is wider than long up to the ninth plate, on which 

 the 2 dimensions are nearly equal ; thence the width decreases faster 

 than the length. Granulation coarse, spaced, and similar to that of 

 abactinal plates, increasing slightly in size on the outer exposed 

 edge of the ray. On a single plate, close to the abactinal plates, is a 

 small pcdicellaria, but these are not a regular occurrence on the 

 superomarginals. The fourth and fifth plates are the largest. 



Inferomarginals lower and narrower than superomarginals, and 

 tumid, the first three being slightly wider than long, the fourth about 

 as long as the width of actinal surface and from here on the width 

 narrows rapidly. (In N. temalis the eleventh plate is longer than 

 wide, in arthrocnemis it is the seventh if the chord of the extreme 

 width is taken and the fifth if the width of the actinal face is con- 

 sidered.) The 10 inferomarginals nearest middle of ray correspond 

 to about 14 adambulacrals (18 or 19 in moluccanus). Granules 

 similar to those of superomarginals, but a trifle larger on ventral 

 surface. All the marginal sutures are deeper and wider than usual 

 in this genus and probably act as fascioles. 



Actinal intermediate plates slightly convex, in 4 chevrons and 

 with three plates interradially next to margin, representing the 

 fifth chevron. The plates of the first chevron reach to the fourth 

 inferomarginal. The plates are covered with coarse spaced hemi- 

 spherical granules less depressed than the marginal. Sutures between 

 the plates distinct and deep. 



First adambulacral with a nearly straight furrow comb of 6 

 slightly flattened four-sided spines tapering to a chisellike edge; 

 second and third with a curved series; on the fourth plate an angle 

 appears near the adoral margin which gradually increases in promi- 

 nence up to the twelfth or fifteenth, and remains prominent to the 

 end of ray. The spines increase to 9 or 10, the 3 or 4 on the apex 



