CONTENTS XVll 



Family I. Mycobacteriaceae Chester, 1901 695 



Genus I. Mycobacterium Lehmann and Neumann, 1896 695 



Genus II. Mycococcus Krassilnikov, 1938 707 



Family II. Actinomyceiaceae Buchanan, 1918 713 



Genus I. Nocardia Trevisan, 1889 713 



Genus II. Actinomyces Harz, 1877 742 



Family III. Streptonrycctaceae Waksman and Henrici, 1943 744 



Genus I. Streptomyces Waksman and Henrici, 1943 744 



Genus II. Micromunospora ^rskov, 1923 822 



Genus III. Thermoactinomyces Tsiklinsky, 1899 824 



Family IV. Aciinoplanaceae Couch, 1955 825 



Genus I. Actinoplanes Couch, 1950 826 



Genus II. Streptosporangiurn Couch, 1955 828 



Order VI. Caryophanales Peshkoff, 1940 830 



Family I. Caryophanaceae Peshkoff, 1940 830 



Genus I. Caryophanon Peshkoff, 1940 831 



Genus II. Lineola Pringsheim, 1950 832 



Genus III. SimonsieUa Schmid, 1922 833 



Family II. Oscillospiraceae Peshkoff, 1940 834 



Genus I. Oscillospira Chatton and Perard, 1913 834 



Family III. Arthromitaceae Peshkoff, 1940 835 



Genus I. Arthromitus Leidy, 1849 835 



Genus II. Coleomitus Duboscq and Grasse, 1930 836 



Order VII. Beggiatoales Buchanan, ordo nov 837 



Family I. Beggiatoaceae Migula, 1894 837 



Genus I. Beggiatoa Trevisan, 1842 838 



Genus II. Thiospirillopsis Uphof, 1927 840 



Genus III. Thioploca Lauterborn, 1907 841 



Genus IV. Thiothrix Winogradsky, 1888 842 



Family II. Vitreoscillaceae Pringsheim, 1949 844 



Genus I. Vitreoscilla Pringsheim, 1951 845 



Genus II. Bactoscilla Pringsheim, 1951 848 



Genus III. MicrosciUa Pringsheim, 1951 849 



Family III. Leucotrichaceae Buchanan, farn. nov 850 



Genus I. Leucothrix Oersted, 1844, emend. Harold and Stanier, 1955. . . . 850 



Family IV. Achromatiaceae Massart, 1902 851 



Genus I. Achromatiiim Schewiakoff, 1893 852 



Order VIII. Myxobacterales Jahn, 1915 854 



Family I. Cytophagaceae Stanier, 1940 858 



Genus I. Cytophaga Winogradsky, 1929 858 



Family II. Archangiaceae Jahn, 1924 863 



Genus I. Archangium Jahn, 1924 863 



Genus II. Stelangium Jahn, 1915 866 



Family III. Sorangiaceae Jahn, 1924 866 



Genus I. Sorangium Jahn, 1924 866 



Family IV. Polyangiaceae Jahn, 1924 870 



Genus I. Polyangium Link, 1809 870 



Genus II. Synangium Jahn, 1924 877 



Genus III. Podangium Jahn, 1924 877 



Genus IV. Chondrojnyces Berkeley and Curtis, 1874 879 



Family V. Myxococcaceae Jahn, 1924 882 



Genus I. Myxococcus Thaxter, 1892 883 



Genus II. Chondrococcus Jahn, 1924 886 



