54 International Code of Nomenclature 



Rules 9b, 9c. Designation of Nomenclatural Types 



but was not formed in conformity with Rule 3, may be fixed by the Judicial 

 Commission. The nomenclatural type of a taxon of rank higher than family 

 may be fixed at the time of its proposal by the author. If not so fixed, it 

 may be designated by the Judicial Commission. 



NOTE. If subdivisions of families (subfamilies, tribes, subtribes) are recog- 

 nized, one taxon of each category must include the type genus of the 

 family and its name should be derived from the name of the type genus. 



ANNOTATIONS 



Rule 9b. The family name Bacilloceae is derived from the generic 

 name Bacillus, and this is the name of its nomenclatural type. There 

 may be a subfamily BaciUoideae, a tribe Bacilleae and a subtribe Bacil- 

 linae, all with the nomenclatural type Bacillus. 



The nomenclatural type of none of the named subclasses, orders 

 and suborders in bacteriology has thus far been definitely fixed either 

 by designation or by action of the Judicial Commission. 



The family name Enterobacteriaceae has been placed on the list 

 of genera consemayicla to replace the rejected family name Bac- 

 teriaceae. 



RULE 9c. Designation of the nomenclatural type of a genus or subgenus. 



(1) The nomenclatural type (type species) of a genus or subgenus is the 

 name of the single species or of one of the species included when 

 the name of the genus or subgenus was originally validly published. 

 NOTE. The expression "type species" is to be used rather than 

 "genotype" or other expressions when referring to the type species 

 of a genus. 



(2) If the author in the original publication of a generic or subgeneric 

 name definitely selected a type species, this species shall be accepted 

 as the nomenclatural type (type species) regardless of other con- 

 siderations (type selection by original designation). 



NOTE. The meaning of the expression "selected a type species" is 



to be rigidly construed. Mention of a species as an illustration or 



example of a genus does not constitute selection of a type. 



(3) If the author of a generic or subgeneric name in his original publica- 

 tion failed to designate a type species, the type may be selected by 

 a subsequent author, and the author who first makes the choice 

 must be followed unless it can be proved that his choice is not in 

 accordance with the following rules: 



(a) If the genus, when originally published, included but one species, 

 this species shall be the nomenclatural type (type species) (selec- 

 tion by monotypy). 



(b) if the genus, when originally published, included more than one 

 species, the type species selected shall be one of these. However, 

 species inquirendae, species doubtfully referred to the genus, 

 species mentioned as in any way exceptional, species which 

 definitely disagree with the generic description (provided others 

 agree), and species which possess characters stated in the generic 

 description as rare or unusual are to be excluded from considera- 

 tion in selecting the type. 



