Abstract
The prokaryotic generic name Shuttleworthia Downes et al. 2002 is illegitimate because it is a later homonym of the plant genus Shuttleworthia Meisner 1840 and the mollusk genus Shuttleworthia Baker 1941 (Principle 2 and Rule 51b(5) of the International Code of Nomenclature of Prokaryotes). We therefore propose the replacement generic name Shuttleworthella, with type species Shuttleworthella satelles comb. nov. The prokaryotic generic name Tetrasphaera Maszenan et al. 2000 is illegitimate because it is a later homonym of Tetrasphaera Popofsky 1913 (Protozoa, Radiolaria) and of Tetrasphaera Górka 1965 (a fossil dinoflagellate) (Rule 51b(4) of the International Code of Nomenclature of Prokaryotes). We therefore propose the replacement generic name Nostocoides, with type species Nostocoides japonicum comb. nov.