CLASSIFICATION 
S INCE the publication of Linnaeus’ Systema Naturae in 
1758, founding the classification of Lepidoptera that is 
still in use, many changes have taken place in the 
nomenclature of the British butterflies. This is because of 
the continuous advance of our knowledge and the increase 
in the number of orders, genera and species that have been 
discovered since the time of Linnaeus. Such alterations in 
the naming of certain species from time to time have naturally 
caused much confusion. It is, therefore, satisfactory to know 
that quite recently — February, 1934 — the Royal Entomo¬ 
logical Society of London has published Part 2 of the Generic 
Names of British Insects, together with a check list of 
the species of the British butterflies, which becomes the 
permanent International Classification of Lepidoptera. 
There are many changes in both the generic and specific 
names, and the old-accustomed arrangement of the genera 
has been altered ; for instance, the Paptlionidae are now 
placed between the Pieridac and the Hesperiidae , and the 
list is headed by the Danaidae ; consequently, the arrange¬ 
ment of species in the cabinet will be on quite a different 
basis. 
As this new nomenclature is an established international 
rule, the classification adopted in this book is in accordance 
with the list of the British Butterflies as revised under the 
direction of the Royal Entomological Society’s committee 
on generic nomenclature. The list is as follows : 
CHECK LIST OF 
THE BRITISH BUTTERFLIES 
DANAIDAE 
1. Danaus, Kluk, 1802 
1. Danaus pleXippus (Linn., 1758). 
