62 THE VOYAGE OF H.M.S. CHALLENGER. 



davu, Fiji ; between Api and Cape York ; between Arrou and Banda ; off the north and 

 south coasts of Papua ; Arafura Sea ; lat. 46° 46' S., long. 45° 31' E. (Station 146) ; lat. 

 47° 25' S., long. 130° 32' E. (Station 159) ; in several places amongst the Philippine 

 Islands ; between Japan and Honolulu ; Pacific, north of the Sandwich Islands ; lat. 42° 

 43' S., long 82° 11' W. (Station 302) ; lat. 36° 44' S., long. 46° 1G' W. (Station 325) ; 

 lat. 37° 45' S., long. 33° 0' W. (Station 330) ; in many gatherings from the tropical 

 Atlantic between lat. 12° 16' S., long. 13° 44' W. (Station 341) and lat. 32° 41' N., long. 

 36° 6' W. (Station 354). 



If the Challenger collections may be taken as a fair indication, this would 

 seem to be the most abundant and most widely distributed of all the pelagic 

 Copepoda. 



At the same time the possibility must be admitted of more than one species being in- 

 cluded in the series which I here refer to Euchceta communis. In very many gatherings, 

 though females were abundant no males could be found, and on the characters of the latter 

 sex perhaps some specific distinctions might have been based. As to the females, I have not 

 found any variations which appeared to me of specific value. The form of the male 

 described by Sir John Lubbock as Euchceta sutherlandii, occurs not uncommonly, and I do 

 not doubt is simply the immature male of Euchceta prestandrece ; this view is also taken by 

 Dr. Claus. And though it is difficult to decide the point absolutely from Dana's 

 drawings and descriptions, I believe that the same remark applies to his Euchceta 

 concinna. Nor do I find any sufficient marks to warrant the separation of Euchceta 

 pubescens : the characters given as belonging to this last species I have found not un- 

 frequently in what I take to be mere varieties of Euchceta prestandrece. It would indeed 

 be wonderful if a species so widely distributed did not present many varieties dependent 

 upon race and external conditions. 



If I am right in regarding all Euchcetce with a notched rostrum and a single 

 elongated tail seta as belonging to one species, we may fairly identify it with that 

 described by Philippi as Euchceta prestandrece ; but no other characters of specific value 

 are noticed by that author. Dr. Claus, at any rate, has referred to Euchceta prestandrece, 

 the Mediterranean species figured in his work, which is undoubtedly also identical with 

 Lubbock's Euchceta atlantica. There is more doubt about the reference to Dana's 

 Euchceta communis, though there is nothing in the figures or descriptions, except 

 insufficiency of detail, to discredit that reference. It is scarcely possible that a species 

 so common and widely distributed as that now under discussion should have been missed 

 by Dana : and a more appropriate term than communis could hardly have been applied 

 to it, but if, as appears likely, Philippi's name referred to the same species, it has the claim 

 of priority in date. 



