PREFACE. V 



for specific names throughout (contrary to the usual practice) 

 in all works for the technical details of which I am personally 

 responsible. It might also he argued that the binomial names 

 of species are practically equivalent to proper names. 



"The nomenclature is made to commence from the 10th edition 

 of Linnets ' Systema Naturae' (1758). The starting-point of 

 the 12th edition (1767)^ fixed by the British Association Rules, 

 is invalidated by their admission of exceptions. The Linnean 

 system was practically established in 1758, and was adopted by 

 most naturalists of repute between 1758 and 1767; nor can we 

 always determine Linnd's own species described in 1767 without 

 reference to the more detailed descriptions or figures published 

 by himself and others in earlier works, in which his new system 

 is employed 



" Specific names rejected as synonyms, and subsequently 

 applied to other species of the same genus, appear to me as 

 objectionable as preoccupied names of genera 



" The limits of a genus are always variable, and its characters 

 subject to modification, both according to the increase of our 

 knowledge, and to the divergent views of different entomologists ; 

 hence, although no generic name ought to be issued without a 

 description, yet the fixing of a type, which must always be an 

 identifiable species placed in it when the generic name is used 

 for the first time, appears to be even more important, for no 

 real certainty can be attained without. In fact the fixing of 

 the type of a genus is to the description what the figure of an 

 insect is to the description of a species.'^ 



Supposing the type of a genus not to have been fixed before 

 its subdivision, it will ultimately become the last species placed 

 in it by the original author which does not contradict his name 

 or description, and which has not been separated from it by 

 subsequent authors. The working of these principles may be 

 illustrated by the manner in which the types of the principal 

 genera of European Zyyanidce have been fixed. 



In 1775 Fabricius founded his genus Zygcbua with a very 

 wide extension. 



