GENERIC NAMES OF BUTTERFLIES 13 



carried out. In so far as it was found that this had not been done, replacement 

 names were subsequently published in the Annot. hep. if this was judged to be 

 necessary on taxonomic grounds. 



(c) Determination of the type-species of genera and consequent ascertainment of the 

 status of the names of genera under the Law of Priority 



For by far the greater number of nominal genera the type-species was determined 

 by original designation by the author of the name concerned or was determined 

 automatically by monotypy, one nominal species only having been cited by the 

 original author as belonging to the genus concerned. Nevertheless, there are many 

 hundreds of genera, the determination of the type-species of which rests on subse- 

 quent selection. 



For most of the nominal genera falling in this last group the currently accepted 

 type-designation consists of a statement by some later author that some particular 

 one of the originally included species is the type-species, there being nothing in that 

 statement to indicate whether the author making it was himself then making the 

 type-selection or whether he looked upon himself merely as recording that the 

 species in question was the type-species through action already taken by some 

 unspecified author. Moreover, the widespread acceptance in the mid-XIXth 

 century of the so-called " Principle of Elimination " led to the rejection in many 

 cases of earlier type-selections which under the Code — not then in existence — were 

 perfectly valid. Another misconception entertained by some authors in the same 

 period, which led to the making of invalid type-selections, was the erroneous belief 

 that a type-selection should be treated as acceptable even if the nominal species 

 selected was not cited as belonging to the genus when the name of that genus was 

 first published provided that, in the opinion of the author making the selection, it 

 represented the same taxon as that represented by some nominal species which was 

 originally included. For these and other reasons of a similar kind it was evident 

 from the outset of the present work that a thorough search of the old literature was 

 required, in order to determine as certainly as possible when, where, and by whom 

 one of the originally included nominal species was first validly selected to be the 

 type-species of each of the genera concerned. 



Since the essence of the rule relating to the selection of type-species by subsequent 

 authors is that it is the earliest selection of one of the originally included species 

 which alone is operative, it was decided that the search to be undertaken in the 

 present instance should be carried out chronologically, books and other works which 

 might contain type-selections being examined in the order in which they had been 

 published. This procedure was found to work satisfactorily, for directly the 

 selection of one of the originally included species to be the type-species of any given 

 genus had been found, the generic name in question was eliminated from further 

 consideration, it being necessary thereafter only to examine the literature for possible 

 type-selections for those genera for which no type-species had as yet been determined. 

 On the other hand, this procedure was extremely laborious and time-consuming. 

 First, great care was needed in searching each volume, it being found in numerous 

 cases that valid type-selections had been made in the most inconspicuous fashion, 



