Natura - nature actualia - actual entities Mundus Plinius - physical world naturalia - natural bodies Biota Domain Bacteria Woese et al. 1990 Superphylum Terrabacteria Battistuzzi et al. 2004 Phylum Firmicutes corrig. Gibbons and Murray 1978 (Approved Lists 1980) Class Clostridia Rainey 2010 Order Clostridialesᵀ Prévot 1953 (Approved Lists 1980) Family Clostridiaceaeᵀ Pribram 1933 (Approved Lists 1980) Genus Clostridiumᵀ Prazmowski 1880 (Approved Lists 1980) Clostridium histolyticum (Weinberg and Séguin 1916) Bergey et al. 1923 (Approved Lists 1980)