14 FRANCIS HEMMING 



some almost parenthetically in a sentence dealing with some other subject. The 

 greater part of the survey described above was concerned with works published from 

 the beginning of the XlXth century — when authors such as Latreille began to 

 select type-species for genera — up to the year 1875 when (as has already been 

 explained) Scudder in his " Historical Sketch " set himself the task of determining 

 the type-species of every nominal genus of butterflies known to him. Writing long 

 before the adoption of the International Code, Scudder in many cases guided himself 

 by rules which were never ultimately incorporated into the Code. In consequence 

 many of the conclusions which he reached in the " Historical Sketch " are incorrect 

 under the present Code. In spite of these inevitable defects this paper of Scudder 's 

 remains by far the most important single contribution to the generic nomenclature 

 of the butterflies published in the XlXth century. After Scudder's time, the 

 entomologists who established nominal genera without designating or indicating 

 type-species became fewer and fewer, and in most cases if a name was published in 

 this way, the deficiency was made good shortly afterwards, sometimes in the next 

 following volume of the Zoological Record, sometimes by the next author to deal with 

 the group concerned. 



The problem discussed above came to an end as from the close of 1930, in the 

 sense that no new genus-group taxon published after that date acquired the status of 

 availability unless, on publication, its author specified its type-species. This 

 decision, which was adopted by the Budapest Congress in 1927, now appears in 

 Article 13(b) in the revised Code. 



The search of the literature described above brought to light a number of previ- 

 ously overlooked type-selections made for the most part in works which had never 

 been studied — or at least had never been thoroughly studied — from this point of view. 

 In some cases the discovery of these earlier type-selections had the effect only of 

 confirming the position of the nominal species currently accepted as type-species, 

 though as from an earlier date and in most cases from a different author. In other 

 cases changes in type-species were involved, but none of these led to any serious 

 disturbances in existing nomenclatorial practice, the names concerned becoming — or 

 remaining — objective or subjective junior synonyms of older names in current use. 

 The search of the literature was carried out as systematically as possible, and it is 

 believed that very few previously overlooked type-selections escaped attention. In 

 view however of the great mass of the literature involved, it would be too much to 

 expect that no t3 r pe-selection had been missed in the search, but it is hoped that the 

 number of such cases is very small. 



(d) Selection of type-species for genera found to be still in need of definition in this way 

 In the course of the search of the literature there was found to be a considerable 

 number of nominal genera, for which no type-species had ever been selected. In the 

 case of genera established in the XlXth century this lack of a type-species was due 

 in many cases to an erroneous belief that the name in question was invalid and there- 

 fore that the selection of a type-species was unnecessary. The generic names 

 incorrectly rejected in this way were for the most part either the names of genera 

 established without included nominal species — a method of publishing a name long 



