252 APPENDIX. No. VII. 



extremely small ; but we find semiglobular bodies of larger size 

 figured in one of Kroyer's plates (' Voyages en Scandinavie,' 

 &c, PI. xli. fig. 2, e, f ), as attached in one case to the ventral, 

 and in the other to the dorsal, surface of Calanus hyjper- 

 boreus. It may be that these are the more mature forms of 

 the parasites now observed on Metridina armata. Now, if 

 the young of such a parasite were attached to the base instead 

 of to the extremity of the maxillipecl, it might very possibly 

 be mistaken for an organ of vision. I feel great hesitation in 

 even hinting at this possibility, knowing the extreme accuracy 

 of Claus' observations ; but the mistake — if a mistake has 

 been made — is one which any observer might easily fall into, 

 more especially since organs, presumed to be supplemental 

 organs of sight, are not unknown among other orders of the 

 Crustacea {Thysanojpocla\ attached to the segments of the 

 body. 



In this same gathering were large numbers of Calani, 

 the examination of which has cost me no small amount of 

 labour. I must take another opportunity of giving the 

 grounds on which the conclusions I have arrived at are based. 

 It will suffice now to state that I believe that the whole of 

 these specimens are referable to Calanus Finmarchicus, 

 Gunner, better known to British naturalists under the name 

 of Cetochilus septentrionalis, Grooclsir, and that Calanus 

 magnus, elegans and borealis of Lubbock, and numerous 

 other so-called species, are merely states and conditions re- 

 sulting from differences of the sex and age of our old friend. 

 The very great development in size of the Arctic examples 

 as compared with the British, which results in the young 

 immature forms of the former surpassing in size the fully 

 developed individuals of the latter, has tended much to 

 render the confusion greater. 



A mounted specimen collected by Captain Feilden near 

 the same spot is referable to the same species which was also 

 procured by Dr. Moss in the summer months at the winter 

 quarters of the ' Alert,' lat. 82° 27' N. 



Two very interesting gatherings were made by Dr. Moss 



