70 PROF. F. J. BELL ON THE [Feb. 19, 



In the outer row there are ordinarily two very well-developed spines, 

 though, here and there, three are to be detected. 



None of the ventral plates bear spines ; some of the granules on 

 the more proximal of them are larger than the rest, and form very 

 distinct aggregates. The valvular pedicellaria? scattered among them 

 are small and not very numerous. The poriferous arese on the 

 dorsal surface are arranged in three very regular rows along either 

 side of the arms ; the arese are not very large, and the pores are 

 not numerous. The granules on the upper are larger than those on 

 the ventral surface, and have no pedicellarise scattered among them. 

 Towards the end of the arm the lophial ossicles may project a little, 

 but they never develop spines. Madreporic plate set just between 

 two of the apical spines, irregularly lozenge-shaped, not large. 



The integument is much thicker than in most species of the genus, 

 and the specimen has the dead-white colour which we can imagine 

 0. chinensis would have had had it been preserved in spirit. 



Measurements : — R=l 16 ; r=35 ; greatest breadth of arm 28. 



Hab. Billiton. 



Oreaster nodosus. 



Pentaceros tvrritus, Perrier, Rev. Stel. p. 240. 



Asterius nodosa, Linnaeus, Syst. Nat. ed. xii. p. 1100 (pars). 



Prof. Perrier prefers Linck's name to that of Linnaeus, whom, 

 indeed, he abstains from directly quoting, his only reference being to 

 Gmelin's edition of the ' Systema Naturae.' 



R=2 , 5 r to 3 r. Disk considerably elongated ; arms long, rather 

 narrow. Lophial line well marked, with prominent rounded projec- 

 tions ; the apical spines very prominent, and a central one typically 

 developed. 



About 30 superomarginal, and one or two more inferomargiual 

 plates ; hoth sets obscure, and without any spines, the lower alto- 

 gether confined to the actinal side. 



Adambulacral spinulation diplacanthid ; ordinarily seven spines in 

 the inner row, of which two or three in the middle are distinctly 

 longer than those at their sides. In the outer row three spines, 

 about twice as stout as those of the inner row ; between the two rows 

 there stands a well-developed forcipiform pedicellaria. 



The separate ventral ossicles are a good deal obscured by the 

 coarse granulation with which they are covered ; the only region in 

 which there can be said to be a distinctly serial disposition of the 

 plates is that which extends along the side of the ambulacral groove. 

 Many of the investing granules are more than a millimetre in length 

 along their longest axis, and the sessile valvular pedicellarise are very 

 numerously represented. A similar coarse granulation is found on 

 the marginal plates ; but any resemblance to O. lincki is opposed by 

 the development of a very large number of pedicellarise '. 



The upper surface might almost be said to be one mass of pedi- 



1 Have wo not here another example of the kind of balance that obtains 

 between the development of spines and of pedicellaria; ? Of. the case of A&tcrias 

 glacialis, Zool. Anz. 1882, p. 283- 



