Procaryotic Genera Domain "Bacteria" Woese et al. 1990 Phylum Proteobacteria Garrity and Holt 2001 see Phylum Proteobacteria Garrity et al. 2005 Class "Alphaproteobacteria" Garrity and Holt 2001 nom. nud. see Class Alphaproteobacteria Garrity et al. 2006 Order Rickettsiales Gieszczykiewicz 1939 (Approved Lists 1980) Family "Holosporaceae" nom. inval. see Family Holosporaceae Görtz and Schmidt 2006 1 Genus Holospora (ex Hafkine 1890) Preer and Preer 1982 see Genus Holospora (ex Hafkine 1890) Gromov and Ossipov 1981 2 Genus Caedibacter (ex Preer et al. 1974) Preer and Preer 1982 3 Genus Lyticum (ex Preer et al. 1974) Preer and Preer 1982 4 Genus Polynucleobacter Heckmann and Schmidt 1987 5 Genus Pseudocaedibacter Quackenbush 1982 6 Genus Symbiotes Philip 1956 (Approved Lists 1980) 7 Genus Tectibacter (ex Preer et al. 1974) Preer and Preer 1982 8 Genus Odyssella