Reduction in number of anaerobic Corynebacterium species is proposed. C. liquefaciens, C. pyogenes, C. granulosum, C. parvum, C. diphteroides (sic) and C. anaerobium are synonyms of C. acnes (Gilchrist) Eberson 1918 and should be so treated. Evidence is presented separating C. acnes from the genus Propionibacterium where recent proposals have placed it. C. acnes NCTC 737, ATCC 6919 is proposed as neotype strain.