18G Report on the Rules of 



were first published, the author of the specific name is 

 to be placed in parentheses. 

 2. Where a genus is reduced to subgeneric rank, or a sub- 

 genus is raised to generic rank, the name of the author 

 of the name is to be enclosed in parentheses. 



18. 



When it is desirable to cite the name of a subgenus, this name- is 

 to be placed in parentheses between the name of the genus and that 

 of the species. 



Example : Vanessa (Pyrantels) cardui Linne. 



19. 



a. If it is desired to cite the name of a variety or subspecies, such 

 name is written immediately following the specific name. 



b. The citation of a variety or subspecies in binominal form (as 

 Corvus Jcamtschaticus instead of C. corax Jcamtschaticus) is not 

 permitted (see Rule 33). The introduction of the words " varietas " 

 or " subspecies " or their abbreviations " var." or " subsp." is there- 

 fore not necessary. 



Examples : liana esculenta marmorata Haliwell, but not Corax 

 Jcamtschaticus instead of Corvus corax Jcamtschaticus. On hybrids 

 see Rule 34. 



V. Subdivision and Union of Genera and Species. 



20. 



When a genus is divided into two or moro restricted genera, the 

 original name must be retained for one of the restricted genera ; if 

 a type species has been proposed, the division containing that 

 species must retain the (otherwise valid) generic name. 



The name of the typical subgenus must be the same as the name 

 of the genus. 



21. 



If the original type of the genus is not clearly indicated, the 

 author who first subdivides the genus may apply the original 

 generic name to such restricted genus as he may judge advisable, 

 and such assignment is not subject to subsequent modification. 



In no case, however, can the original name be transferred to a 

 group containing none of the species originally included in the genus 

 or which the author of the original genus doubtfully referred to it. 



22. 



The division of a species into two or more restricted species is 

 subject to the same rules as the division of a genus. But a specific 

 name which undoubtedly rests upon an error of identification cannot 

 be retained, even when the species are afterwards placed in different 

 genera. 



