THE BALTIC SEA 329 



Table 135 



No. of Chironomid specimens per m 2 



Twerminn Pellinge 



June-July September September 



1926 1928 1922 



Depth, m 



Maximum numbers of specimens and biomass. In conclusion we give the data 

 for the maximum indices of the biomass, and the numbers of specimens of 

 various bottom forms off the Finnish shore of the Gulf of Finland according 

 to Sagerstrale (Table 136). 



Table 136 



S. Sagerstrale (1944, 1957) distinguishes as an individual biocoenosis the 

 overgrowth of Fucus vesiculosus. It consists in a high proportion of the 

 crustaceans Gammarus (zaddachi) oceanicus, G. zaddachi salinus, G. zaddachi, 

 Idotea granulosa, I. baltica, I. viridis, Taera albifrons (marina), Praunus 

 flexuosus, P. inermis, Leander adspersus fabricii, Mytilus edulis, the Cardium 

 edule fry, Balanus improvious, Laomedea loveni, Membranipora crustulenta and 

 Pelmatohydra oligactis, which attach themselves to the algae. The fresh- 

 water elements are represented by Theodoxus fluviatilis, Limnaea peregra 

 (ovata) and by chironomid larvae. In more enclosed places there are also the 



