The nomenclatural analysis of Cloeon simile Eaton and C. praetextum Bengtsson stat.nov. and the discussion of morphological differences between these species for all development stages were carried out on the basis of material from Middle and Western Europe. A neotype of C. praetextum was designated from Bengtsson's original collection. The description of nymphs and imagines of C. schoenemundi Bengtsson and imago male of C. degrangei n.sp. are given on the basis of material from France. The taxonomic validity and systematic position of the species C. hovassei (Verrier), C. rabaudi (Verrier) and C. languidum Grandi are discussed. Remarks on the distribution and ecology of some of the more abundant species are included.