6 Introduction 



Schouten Islands, and on collections received from Dutch New Guinea, 

 Waigeu, Mefor, Mysol, Key, Aru, Tenimber, Obi, Central Ceram and 

 the Sula Islands. 



It is proposed to monograph the genus Delias, and material to this 

 end is being accumulated. Certain studies on Mimicry phenomena are 

 also in contemplation. 



4.— PBINCIPLES ADOPTED IN THE CLASSIFICATION OF 



SPECIMENS. 



We accept the terminology in use by the majority of systematists, 

 and distinguish between a geographical race, an individual variation, 

 and a seasonal variation. We also agree that a figure of any sufficiently 

 distinct form should be given whenever convenient, but do not consider 

 the absence of such a figure to be entirely prejudicial to the description, 

 and in any case no figure is of value unless accompanied by a descrip- 

 tion, however brief. 



The individuals of a species are grouped under their various races 

 and arranged in geographical order as far as convenience permits. The 

 individuals of each form are grouped according to locality or zoological 

 area, the sexes being sorted in every such series. Any type specimens 

 are placed at the end of a series comprising the form named. The 

 name-label placed at the bottom of a series bears the original type- 

 locality. 



Where known forms are absent in the collection, a name-label, with 

 figure if available, is placed in the position of the missing form. 



Families are arranged geographically instead of in any so-called 

 phylogenetic order. The phylogeny of the forms of Lepidoptera cannot 

 be said to be correctly understood at present. Not only does the 

 geographical arrangement help us to an understanding of phylogenetic 

 relationships, but it is of great value in finding any desired form in a 

 great collection, and enables one to get some idea of the forms occuring 

 in a given area. 



A card-index catalogue of the collection was commenced in 1915. 

 Each card bears the name of the species with its original reference, 

 also the number of the drawer in the collection, and a list of the 

 localities of the specimens. A separate index is made for types. These 

 indices are yet far from complete, but are compiled whenever a group 

 is properly worked through. 



