632 



DEPTHS OF THE OCEAN 



In the southern section, again, the majority were taken in the 

 western half towards the Sargasso Sea, west of the longitude of 

 the Azores, where these forms occurred in great abundance. 



The distribution of salpae is somewhat different. Certain 

 forms occur only in the south, for instance, Cyclosalpa floridana, 

 Salpa amboinensis, and S. henseni ; but the majority were taken 

 to the north and south of the Azores, for example, Cyclosalpa 

 pinnata and Salpa inaxwia. The medusa Pelagia perla is 

 similarly distributed. All these surface animals occur in this 

 central region of the North Atlantic in such countless numbers 

 as to be immediately noticeable, and it struck me at the time that 

 this peculiar distribution north and south of the Azores might 

 be correlated with the submarine ridge on which these islands 

 are situated. The currents are probably influenced by the 

 configuration of the bottom, and the distribution of the pelagic 

 organisms, even in the surface waters, may possibly be thereby 

 affected, as we have often observed during previous cruises of 

 the " Michael Sars " in the Norwegian Sea. A third group of 

 salpae, viz. Salpa fusifonnis, S. mucronata, S. confcederata, and 

 S. zonaria, while certainly most abundant north and south 

 of the Azores, occurred frequently in other localities, especially 

 in our northern section. Salpa fusiforviis was doubt- 

 less the principal form among these, and was the only one 

 observed. at all the stations to the south-west of Ireland, between 

 Rockall and the west coast of Scotland, and towards the Faroe- 

 Shetland channel. Fig. 479 illustrates the distribution of Salpa 

 zoiiaria, which was found abundantly in the northern part of 

 the Atlantic. 



Most of the squids taken at the surface occurred south of 

 the Azores, especially larval forms, and included larvae of 

 Onychoteuthidae, Octopodoteuthis sictda, Cranchiidae (Cranckia 

 scabra, Teuthowenia megalops, GalitetUhis sukniii), Heteroteuthis 

 dispar, Tremoctopus atlaiiticiis, and Argonauta. Certain north- 

 ern forms like Gonatiis may be supposed to be wholly boreal. 



Among oceanic surface fish the Scopelidae are probably 

 most abundant. They were taken in thousands, but only a 

 few have as yet been determined. Of these, Myctopkum 

 rissoi, M. benoiti, M. affine, M. humboldti, M. coccoi, 

 M. ckcerocephahi7n, M. gemellari, M. maderense, M. warmingi, 

 M. 77iicropterum, and M. gemmifer were taken only in the south ; 

 while M. glaciale, M. punctatuvi, and M. rafinesquei were also 

 taken in our northern section. The Scopelidae were usually 

 accompanied by numerous young fish, of which I may mention 



