THE SEA OF OKHOTSK 



807 



pacifica, reaching 1 m in height, and comparatively small but exquisite fan- 

 like colonies of Plumarella longispina, Caliptrophora ijimai and others are 

 adapted to the upper division of the continental shelf. On the soft soils of the 



MORE THAN SO 



25-50 

 10-25 

 | I LESS THAN 10 



Fig. 401. Quantitative distribution (in g/m 2 ) of soil-swallowing benthic forms of the 



Sea of Okhotsk (Savilov). 



upper horizon large patches are occupied by the Brisaster latifrons biocoe- 

 nosis.' 



The fauna of the lower horizon of the bathyal zone (750 to 2,000 m) and 

 of the abyssal zone, considerably impoverished both qualitatively and quan- 

 titatively, are characterized also by a series of colourful forms (Fig. 406, 6-1 1) : 

 the Foraminifera Bathysiphon ; the Porifera Cryptospongia enigmatica pierced 

 by the long tube of the polychaete Potamilla symbiotica ; the single madre- 

 poric coral Caryophyllia clavus ; the sea- whip Radiceps verrillii ; the decapod 



