vi Introduction. 



then we shall have the Culicidae in the unsatisfactory position of 

 having dual names. Surely the synonomy is bad enough already 

 without this. 



Again, it must be pointed out. that the larval characters 

 which have been chosen for descriptive work are by no means as 

 stable as one has been led to believe. 



The main characters taken are the number and form of the 

 " scales " of the comb and pecten in Culicines, and the frontal 

 hairs in Anophelines, also the form of the siphon in the former. 



Any one who has examined a large series of any larvae will 

 notice a wide range in these characters, not only in different 

 stages of the same species, but in the same species in the same 

 stage. It is quite possible that we may have the larva of one 

 species being described as several different species. 



The enormous amount of material at disposal since the 

 inception of this volume has still further shown the value of 

 scale structure, not only for diagnostic work but also as a means 

 of true or natural classification, for it is found that grouping by 

 these characters aided by others of minor importance such as the 

 male genitalia and palpal structure agrees with what we know of 

 their bionomics. The various new methods of classification 

 suggested by other workers are referred to on pages 9 to 17. 



With the exception of the adoption of a few characters in an 

 admirable theme of general classification drawn up by Dr. Lutz, 

 no changes have been made in this volume. 



The exclusion of the Corethrinae and their elevation to family 

 rank was suggested in the first volume (p. viii.). 



Some alterations have been made in regard to the terms used 

 in the description of the leg. The metatarsus is called the first 

 tarsal, and the more distal segments are called tarsal segments, 

 or tarsals. The original descriptions of other workers have also 

 been altered in this respect. What has been previously called 

 the first tarsal must now unfortunately be called the second 

 tarsal, and so on. 



It was hoped at one time that all recent literature on this 

 subject might have been incorporated as a bibliography, but the 

 • mount of writing during the past three years has been so great 

 that it, is impossible. The literature on this subject is now so 

 voluminous that it might well be issued as a separate volume. 



Amongst the most important works that have appeared since 

 1903, we must mention the following : — " Os Mosquitos no Para," 

 by Dr. E. A Qoeldi (1905) ; " Mosquitos do Brazil," by Celestino 



