In the distributional study of Pisidium lilljeborgii Clessin the author states the presence of this species in materials collected by dr Miyadi, 1934 in the northern Kuriles and preserved in the Swedish State Museum of Stockholm. The question arises whether the northern and southern Kuriles are different faunically as to Pisidium. A revised map of the geographical distribution of P. lilljeborgii in central, western and northern Europe is given. Some subareas may be distinguished.