62; 



DEPTHS OF THE OCEAN 



species found in depths below 500 or 1000 metres may in 

 other locaHties nearer the polar regions reach the surface. 



During the Atlantic cruise of the " Michael Sars " numerous 

 arctic or northern forms were found in deep water in company 

 with the genuine or permanent deep-sea animals, especially in 

 our northern section from Newfoundland to Ireland. We 

 succeeded in proving the continuous occurrence of such forms 

 from the cold water-layers off the Banks of Newfoundland 

 down to great depths, just as these cold water-layers have 



Qbnostoma grande 



Fig. 477. 



proved to be directly connected with the deep layers of the 

 ocean (see pp. 658-659). 



Pelagic Commttnities in Depths between 1^0 and 500 

 Metres. — At the upper limit of the bathypelagic region in 

 about 500 metres certain fish, entirely different from the 

 bathypelagic species, make their appearance along with 

 CyclotJione signata. These fish are as a rule laterally com- 

 pressed, with a mirror-like silvery skin ; when coloured, the 

 back is generally blackish brown, and the resplendent mirror- 

 like sides of the body blue or violet. The eyes are large, 



