CTENOPHORA. 



95 



Against this assertion I would recall the statement of Wagner, that he has found Cestus veneris and 

 Beroe Forskalii in the White Sea; this occurrence of these two forms can only be explained in this 

 way, that they have been carried thither by the Gulf Stream'). — Though it must be agreed that the 

 statement of Wagner cannot be regarded as beyond doubt ( — and the same applies to Walter's 

 record of two species of Bcroi\ one of which would evidently be B. Forskalii, at Spitzbergen — ), I must 

 regard it as ver}' probable that such warm-water Cteuophores will prove to occur in the North 

 European Seas, from the Skagerak along the Coasts of Norway, and probably sometimes so far North 

 as both Spitzbergen and the White Sea, it being a well known fact that the Gulf Stream makes its 

 influence felt so far North. 



It is a well known fact, first recorded by M. Sars (Fauna littoralis Norvegise I. 1846.), that 

 both Salps and large Siphonophores are sometimes carried in great numbers to the coasts of Norway; 

 and this is a phenomenon occurring, generally in September — November, most years. That these forms 

 are carried to the Norwegian Coasts with the Gulf Stream, nobody can doubt. But it seems very improb- 

 able that such Cteuophores, which otherwise occur together with these animals in the Gulf Stream, 

 should not also be carried along together with them to the North European Coast — viz. such forms as 

 Cestus Veneris and Beroe Forskalii. Besides these also other forms might be expected — I would 

 name e. g. Eucharis., Tiner/e, Horviiphora. I had hoped to be able to give the definite proof of the 

 correctness of this suggestion, but, unfortunately, last year (1911) proved to be exceptional, in that the 

 Salps did not appear at the Norwegian Coast, either during my stay at Bergen and Trondhjem or 

 later in the fall of that year. That careful observations of the pelagic organisms accompanying the 

 Salps will prove at least some of the Cteuophores named to be among them I cannot doubt. 



As mentioned above (p. 73) Moser regards the occurrence hi Pleurobrachia pileiis in both the 

 arctic and antarctic Seas as "ein Fall von Bipolaritat . . . , wie er bis jetzt nur bei ganz wenig Arten 

 nachgewiesen ist" (Op. cit. p. 144). Later on in the same work (p. 182) the author states that the arctic 

 and antarctic fauna have only the two species Pleurobrachia pileus and Beroe cucuniis in common, the 

 accordance being thus as regards the Cteuophores "eine recht geringe, eine viel geringere, wie sie 

 nach der Pfefferschen Reliktenteorie sein miisste, um so mehr da diese beide keine eigentlich bipo- 

 laren Formen . . . sind". With this I quite agree. There is really no case of bipolarity among the 

 Cteuophores, the two forms named being, in fact, continuously distributed from the arctic to the 

 antarctic region; nor do they only occur in deeper water in the intervening tropical regions, as is 

 suggested by Moser (loc. cit). This becomes evident from the facts recorded by the author herself. 

 Thus the specimens of PI. pileus recorded from the Seychelles are stated to have been taken at the 

 surface; that the specimen from the North of Ascension was taken in a haul from 200"', can, of 

 course, not prove the contrary. That these species may perhaps be less common in the tropical 

 than in the more temperate seas, as Moser suggests (p. 171), is possible, though it can by no means be 

 regarded as an established fact. But the main point in this matter is that the two species in question 

 have been definitely shown to be continuously distributed from the arctic to the antarctic region. 



M The fact that Beroe Forskalii is recorded bj' O. Maas (Meduses. Expedition antarctique Francaise 1903 — 5 (Charcot). 

 190S. p. 16) from the Antarctic Sea does not alter the fact that the occurrence of this species in the North European Seas must be 

 regarded as a proof of the existence of Gulf Stream water in the place, where it is found. 



