38 " ENDEAVOUR " SCIENTIFIC RESULTS. 



a series of 2 or 3, and then a single plate, against the infero- 

 marginals, completes the covering of the area ; all these plates, 

 tend to overlap inwardly and proximally ; all are l.earers 

 of granules like those on the inferomarginal plates. Adambu- 

 tacral plates about 40, at first wider than long, but rapidly 

 decreasing in breadth and becoming twice as long as wide • 

 distal to middle of arm there are about 7 adambulacrals to 

 about 5 inferomarginals ; the furrow margin is at first nearly 

 straight, but soon becomes convex and then the convexity 

 becomes more and definitely restricted to the adoral end ; 

 distal to the middle of the arm, these convexities on plates of 

 opposite sides tend to meet across the furrow, the bridges, 

 thus formed alternating with conspicuous pores where the 

 plates are not in contact ; proximally there are 6 or 7 blunt, 

 somewhat angular, more or less flattened spines, about half a 

 millimeter long on the furrow margin of each plate ; th& 

 middle spines are longest, the proximal and distal shortest ; 

 on the plates distal to arm-middle there may be 8 or 

 9 spines in the series, but they are decidedly shorter ; 

 outside the marginal series is a parallel set of 3-5 much 

 smaller, thicker spines or high granules, and external 

 to it a parallel series of 5-6 granules like those on the 

 actinal plates ; additional similar granules may occur between 

 the two external series or outside the outer one ; the adambu- 

 lacrals may thus be about as well covered with granules as 

 any of the actinal plates. Oral plates neither conspicuous nor 

 peculiar, only the proximal spines enlarged and they not very 

 greatly. Pedicellariae none. Colour gray, more yellow 

 beneath ; nearly white where the granules are rubbed off. 



The markedly pentagonal abactinal area, the flat and over- 

 hanging interradial superomarginals, the adambulacral arma- 

 ture and the general proportions remind one very strongly of 

 N. albidus, from the tropical Atlantic, but the adambulacral 

 spines are angular and flattened in the Australian species and 

 eight superomarginal plates, instead of six, make up the disk 

 boundary on each side. None of the species from the Indian 

 Ocean and Philippine Islands seem to be any nearer than 

 N. albidus to this South Australian species. 



Loc— Great Australian Bight, 129° 28' E., 250-450 fathoms. 

 One specimen. 



