202 



One of the areas of the sublittoral where there are accumulations of sea- 

 wrack, along the northern shore of the Kandalaksha Bay, has been the 

 subject of minute analysis by G. Gurvich and T. Matveeva (1939). 'The fades 

 of this biotope ', they write, ' is sufficiently varied even at first glance. Numbers 

 of spiders run over the surface of the wrack, deeper down there crawl different 

 Apterygota and mites, more rarely quick-moving beetles (Carabidae) and 

 also myriapods can be seen. Still deeper Oligochaeta creep about in huge 

 numbers, sometimes huddling together in whole bunches. At the very bottom 

 of the layer of wrack amphipods are met with and in particles of cortex 

 saturated with moisture, and in humus, live little characteristic Harpacticoida.' 

 An account of the number of animals in the heaps of sea-wrack, which are 

 often several metres wide and as much as half a metre thick, is given in 

 Table 87 and Fig. 88. 



As may be judged from the data of the table, Oligochaeta constitute 

 96-05 per cent of the whole population of the heaps of sea-weed. Arachnoidea 

 predominate in the top layer, Apterygota in the middle, and Oligochaeta in 



Table 87 



