Following the recent discovery of seven new species, ten specific taxa are now recognized within the genusBacillus:1.B. rossius;2.B. grandii;3.B. whitei;4.B. lynceorum;5.B. atticus;6.B. diplocarius;7.B. carius;8.B. rhodius;9.B. cyprius;10.B. creticus.Furthermore, eight subspecies have been defined withinB. rossius.The distribution and the ecology of the species are summarized. On the basis of ootaxonomy, karyology, electrophoretic allozyme analysis and vitellin comparisons, the phyletic relationships among taxa within the genus are suggested, with particular emphasis on the natural thely‐tokous hybrids,B. whiteidiploid and the triploidB. lynceorum.The main evolutionary mechanisms at work here appear to be: interspecific hybridization, polyploidy, chromosome repatterning and the switch to parthenogenetic reproduction. Gradual genetic differentiation has produced subspecific taxa inB. rossius.