SUMMARYA number of morphological and reproductive similarities between members of the genusDictyuchusand those ofAchlyaprompted the present study of enzyme activities ofDictyuchus monosporus.Specific activities of phosphofructokinase, aldolase, isocitrate dehydrogenase, malate dehydrogenase, cytochrome oxidase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, lactate dehydrogenase, alcohol dehydrogenase, and catalase inDictyuchuswere determined. The activities found were in general comparable to those found inAchlya ambisexualis, with the exceptions of glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, whose activities were considerably lower inDictyuchus.