728 



BIOLOGY OF THE SEAS OF THE U.S.S.R. 







50 00 



6000 



7000 



8000 



9000 



Fig. 353. Vertical distribution of certain species of Gam- 

 maridae (Birstein and Vinogradova). 1 Cyphocaris chal- 

 lenged ; 2 Cyclocaris guilemi ; 3 Eusirella multicalceola ; 4 

 Rhaehotropis natator; 5 Koroga megalops; 6 Parandania 

 boeeki ; 7 Paracallisoma alberti ; 8 Cleonardo mawocephala ; 

 9 Astyra bogorovi; 10 Halyce shoemakeri', 11 Cyphocaris 

 richardi; 12 Ля/уга zenkevitchi; 13 Halyce aculeata; 

 14 Tetronychia gigas; 15 Vitjaziana gurjanovae. Zones 

 undoubtedly inhabited are coloured black, zones of pos- 

 sible habitat are cross-hatched. 



endemic species are practically absent from the upper abyssal sub-zone; in 

 the abyssal they constitute 50 per cent, and in the ultra-abyssal 100 per cent. 

 To a certain extent, however, this is accounted for by the deep-water fauna 

 not having been sufficiently studied. 



Abyssal plankton of the northern part of the Pacific Ocean contains not 



