Procaryotic Genera Domain "Bacteria" Woese et al. 1990 Phylum Proteobacteria Garrity and Holt 2001 see Phylum Proteobacteria Garrity et al. 2005 Class "Gammaproteobacteria" nom. inval. see Class Gammaproteobacteria Garrity et al. 2005 Order "Legionellales" Garrity and Holt 2001 nom. nud. see Order Legionellales Garrity et al. 2005 1 Family Legionellaceae Brenner et al. 1979 (Approved Lists 1980) [monotypic] 2 Family "Coxiellaceae" Garrity et al. 2001 nom. ined. see Family Coxiellaceae Garrity et al. 2005