68 BRITISH COPEPODA. 



in the specimens here described, differ somewhat from 

 those given by Thorell, who had seen only one speci- 

 men, a female. The accuracy of my own drawings I 

 have verified by reference to several specimens, and it 

 is, perhaps, better for the present simply to amend 

 M. Thorell's description than to introduce another 

 specific name on the strength of these not very impor- 

 tant differences. M. Thorell asserts dubiously the 1- 

 branched character of the fourth foot ; of this character 

 there can be no doubt, nor, so far as I have been able to 

 ascertain, of the entire absence of the fifth pair. The 

 Scandinavian specimen on which the genus is founded, 

 though taken in the open sea by Prof. Lilljeborg, is 

 nevertheless supposed by M. Thorell to be a true 

 internal parasite. In this supposition, however, I 

 cannot concur. Though truly suctorial in structure 

 these creatures may very likely obtain supplies of 

 nutriment from the fronds of algae, from decaying or 

 dead organic matter, as well as by attacking, from the 

 outside, some or other of the invertebrate animals. 

 This, no doubt, is the case with the somewhat simi- 

 larly constituted Ostracoda, Paradoxostoma and its 

 allies. 



The number of joints composing the anterior an- 

 tenna of what I suppose to be the male of this species 

 eleven, as opposed to nine in the female excites a 

 doubt as to whether the two forms are specifically the 

 same. Possibly they are not, but I have, at present, 

 no means of deciding the question. In other respects 

 the two are apparently identical. 



