126 DEPTHS OF THE OCEAN 



for twenty-four hours, taking continuous observations of tempera- 

 ture and salinity at different depths. It was quite evident that 

 there were considerable vertical fluctuations, the intermediate 

 layers showing up and down movements with an amplitude 

 of as much as 35 metres during a period that corresponded 

 practically with the tidal period. 

 Pelagic hauls. After leaving Glasgow we made pelagic hauls with our 



silk nets and young-fish trawls on the coast bank, on the slope, 

 out in the deep channel, near the southern flank of the Wyville 

 Thomson Ridge (Station loi), and to the north of it (Station 102), 

 At every depth our catches to the south of the ridge closely 

 resembled those we made in our northern Atlantic section 

 between Newfoundland and Ireland, and particularly the catches 

 made in the eastern portion of that section. 



In the upper layers there were all the boreal animals 

 characteristic of Atlantic water in the Norwegian Sea, as, for 

 instance, Eiithemisto and Clione liniacina. But there was also a 

 mass of Atlantic forms that do not occur all the year round in 

 the Norwegian Sea, though they are known to wander in at 

 certain seasons of the year, as at the end of the summer or 

 during autumn. The tow-nets gave a mixture of ^r«^/^;2«^/2i", 

 Salpa fusiformis, numbers of scopelids, leptocephali (full- 

 grown larvse of the common eel), the young of Macriirus, and 

 Nerophis csquorezis. 



At a depth of 300 metres we captured the silvery Argyro- 



pelecus, and in deep water, from 500 metres downwards, there 

 was the characteristic fauna of black Cyclothone microdon, 

 red crustaceans [Acantkephyra), and other forms, which thus 

 occur right tip to the southern slope of the Wyville Tho^nson 

 Ridge. 



On the northern side of the ridge we towed our appliances 

 at 50, 100, 150, 200, 300, 500, 700, and 750 metres (Station 102) 

 without catching a single specimefi of these Atlantic deep-sea 



forms ; but in the upper layers there were not merely boreal 

 forms, but also salpae, the area of distribution of which is 

 mainly Atlantic. 



These results quite accord with our previous observations 

 during the cruises of the " Michael Sars." Hauls in the deepest 

 waters of the Norwegian Sea have not yielded any pelagic fish 

 other than the black Paraliparis bathybii (Fig. 107), which 

 used to be considered a bottom-fish ; it is interesting to note 

 that it is black. There was a complete absence of Cyclothone 

 and the red Atlantic crustaceans belonging to the genus Acan- 



