REPORT ON THE ASTEROIDEA 321 



to that described in Nectria ocellata. This singular admixture of characters in the adult 

 and in the young forms has made me hesitate before referring these examples to Nectria 

 ocellata, and has, at least in my mind, thrown a doubt upon the validity of the separation 

 of Nectria ocellata as a species distinct from Nectria ocelli/era. As this can only be 

 settled by the study of a larger series of both old and young forms than I have been able to 

 consult, I have referred the examples under notice to the original species, Nectria ocelli/era. 



Subfamily Goniodiscinje, Sladen, 1888. 

 Genus Stellaster, Gray. 



Stellaster, Gray, Ann. and Mag. Nat. Hist., 1840, voL vi. p. 277. 



Gcmiaster (subgen. Stellaster), von Martens, Arohiv f. Naturg., 1865, Jahrg. xxxi., Bd. i. p. 356. 

 Pentagonaster (subgen. Stellaster), Perrier, R6vis. Stell. Mus., p. 196 (Archives de Zool. expdr., 1876, 

 t. v. p. 12). 



I consider that this genus well merits independent recognition, and that in any case 

 its structural characters do not justify its being regarded as a mere subdivision of the 

 genus Pentagonaster, unless the limits of that genus are made much more extended than 

 has ever yet been proposed by any classifier. To take such a step would be in my opinion 

 to ignore altogether what should be recognised as the characters of a genus, and would 

 almost necessitate a reversion to the old idea of a genus founded on single arbitrary 

 characters rather than on the consideration of the affinities and differences of its mor- 

 phological structure as a whole. 



Stellaster is in many respects structurally related to Goniodiscus, as limited by M. 

 Perrier, and I have placed them in the same subfamily. 



Cliorology of the Genus Stellaster. 



a. Geographical distribution : — 



Pacific : Two species between the parallels of 40° N. and 20° S. 



Stellaster equestris and Stellaster tuberculatus from China ; the 

 former also from Japan and Formosa, and extending to Australia. 



Eastern Archipelago : Five species between the parallels of 20° N. and 20° S. 

 Stellaster equestris (which extends northward to China and Japan), 

 Stellaster gramdosus, Stellaster squamulosus, and Stellaster incei, 

 from Australia ; the last named also from Amboina, New Guinea, and 

 Sumatra. Stellaster incei was collected by the Challenger in Torres 

 Strait and the Arafura Sea, and amongst the Philippine group. Stel- 

 laster princeps from Torres Strait. 

 /S. Bathymctrical range : As at present known all the species are confined to the Lit- 

 toral zone : the greatest recorded depth is Stellaster squamidosus, 60 fathoms. 

 (zool. chall. exp. — part li. — 1888.) 41 



