76 ECHINOOERMA OF THE TnDIAN MuSEUM, r A HT VII. 



Depth. — Littoral, and down to 160 fathoms. 



Remarks. — The occurrence of this species at depths of lOo and l(i(i fathoms 

 in the East Indian archipelago is a fact of very great interest, and it is to be 

 regretted that tlie precise localities in these two cases were not recorded. Littoral 

 species very rarely reach the 100-fathom line, and still more rarely pass it The 

 occurrence of Antrdon bifida on the Rockall Bank below 100 fathoms, while 

 scarcely reaching that depth anywhere else, has been thought possibly to be due 

 to a subsidence of that bank which carried the animals down much deeper than 

 they would ever have descended voluntarily. If these specimens of CapiUaste)- 

 muUiradiata could be shown to have been obtained close to islands which can be 

 proved geologically to have subsided, then a great degree of probability would l)e 

 conferred upon the supposition regarding Rockall. 



Among the West Indies we meet with a somewhat similar case ; Tropiumttru 

 picta and Neinaster linecUa are common littoral species along the Brazilian coast 

 but both in the West Indies inhabit water 150 fathoms or more in depth. 1 have 

 explained this by supposing that, creeping northward from Brazil, these two 

 species found it necessary to descend to a considerable depth in order to pass 

 under the mouths of the Amazon and the Orinoco, and, having reached a depth 

 at which such passage was possible, they continued northward at that depth 

 instead of again rising toward the surface, a process whicii, on account of the 

 peculiar larval conditions pertaining to the crinoids (as we understand them), 

 would be exceedingly slow. 



Any theory of land subsidence based upon Capillaster muUiradiata, however, 

 would have to be supported by especially strong proof, for the sub-family 

 (.'apillasterina> to which this species belongs has, when compared with the other 

 sub-famiHes of the Comasterida?, an enormous bathymetric range, from the low 

 tide mark (or even between tides) to nearly 500 fathoms, and it may well be that 

 the individual species comprising this family, a number of which we now know 

 only as littond or sub-littoral, will prove to have a bathymetric range of an extent 

 hitherto entirely unsuspected. 



CAPILLASTER MULTIRADIATA var. COCCODISTOMA. 



Comatida coccodistoma 1862. Dujardin and Hupe, Hist. nat. des Zoophytes. 



Echinodermes, p. 208 {no»ien niidinn). 

 Act i nometra coccodistoma 1883. P. H. Carpenter, P. Z. S., 1882, p. 747 (itumen 



nudum). — 1888. "Challenger" Reports, vol. 26, Zoology, p. 'i2() (iioriicii 



nudum) . 

 Capillaster 7)iiiltir(idlatu var. coccodidotiia l!»l(t. A. H. Clark, Proc. U. S. Nat. 



Mus., vol. 40, p. 16. 



Habitat. — Madagascar. 



Depth. — Littoral, and down to .'JO meters. 



