436 Deep-sea Trawling off the S.W. Coast of Ireland : 



III. OpH lUEOI DEA. 

 Opldothrix pentaphyllum, Peim. 



Two large specimens from 200-315 fath., which would, I 

 imagine, be referred to 0. Luetkeni, Wyv. Thorns.* ; I must 

 own, however, that the variations exhibited among the better 

 known littoral representatives of this species are so great that 

 I cannot bring myself to look upon the specimens before me 

 as anything more than large, well-marked individuals of this 

 variable species. 



IV. ECHINOIDEA. 

 Cidaris papillata, Leske. 



Taken at various stations, from 150 to 315 fath. ; as usual, 

 in some localities the species was very abundantly represented. 

 The specimens do not exhibit in any marked degree the varia- 

 tion to which Prof. Wyville Thomson has called attention, 

 for they may all be said to have the spines rather long and 

 slender than stout. In a young specimen the echinulation of 

 the spines is more marked than in those which appear to be 

 adult. 



Phormosoma placenta. 



Phornwsoma 2)lacenta, Wyv. Tli. 



The capture of this species was perhaps the greatest of 

 Mr. Green's achievements ; so far as English naturalists are 

 concerned the disappearance of the Echinids described by 

 Sir Wyville Thomson in the ' Philosophical Transactions ' 

 for 1874 has been a misfortune, as tliey have never had the 

 ■ opportunity of examining this form for themselves ; the other 

 specimens known to have been collected are those which were 

 obtained by the ' Knight Errant ' in the Faroe Channel f, 

 and by the ' Blake ' in American waters; the only naturalist 

 who has, so far as can be gathered, had the opportunity of exam- 

 ining these specimens is Prof. Alex. Agassiz, who has chiefly 

 occupied himself with describing the changes due to growth 

 and discussing the affinities of these forms. Though such 

 investigations are of interest and importance, we are still in 

 need of that more elementary and less exciting information 

 which consists in an adequate knowledge of the species itself 



* ' Depths of the Sea,' p. 100. 



t With, it should be noted, dredging-appai'atus provided at the expense 

 of Sir W. Thomson J cf, Proc. Koy. Soc. Ed. xi. p. 644. 



