Ciliates of the genus Colpoda are widely distributed organisms, commonly found encysted on most types of vegetation and in most soils. Few studies have carefully examined morphometric variation in the genus. Kahl (1931-1935) provided one of the most complete reviews of species in the genus Colpoda. He redescribed 7 species and described 10 new species, primarily basing his distinctions between species on variations in body morphology. Burt (1940) undertook a careful analysis of intraspecific variation in the genus. The major characters separating the species he studied were somatic length, total kinety number, and characteristics of the Feulgen-stained macronucleus. Lynn (1976, 1977) and Novotny et al. (1977) redescribed five common species using silver impregnation techniques and recorded variability within clonal cultures. Recently, Foissner (1980) provided careful drawings and descriptions of 10 species of which 4 are new. (ref. ID; 7205)