74 A. INGRAM AND J. W. SCOTT MACFIE. 



Following Bacot we have described the pupal paddles of a few mosquitos which, 

 so far as we know, have not yet been illustrated in this particular manner. It 

 seemed to us, after reading Bacot's paper, that, while helpful in the differentiation 

 of certain species, a scheme of classification based solely upon the characters of 

 the pupal paddles with their appendages would break down sooner or later. We 

 must admit, however, that this break-down has not occurred so far as the 

 examination of our materials has gone, yet the points of distinction are sometimes 

 so slight that we believe that not only the numbers and arrangement of the setae 

 on different parts of the pupal case should be taken into consideration, as suggested 

 by Howard, Dyar and Knab, but also in certain cases the length and shape of the 

 pupal trumpets, in attempting to draw up a scheme of classification based upon 

 pupal characters alone. Such a provisional scheme we have outlined below for 

 the pupae which have been figured by Wesche and Bacot, and for those we 

 ourselves have had the good fortune to examine. Unfortunately we have not been 

 able to avail ourselves of all the descriptions given by Wesche, as some of them 

 are incomplete and his drawings, which were made at a low magnification, do not 

 reveal certain minute points on which we have had to rely for the differentiation 

 of species ; this is especially the case in the genus Culex, in which we have had 

 reluctantly to abandon the attempt to include his species in our scheme. 



In drawing up this scheme we have relied as far as possible on the characters of 

 the paddles and the setae on the last two abdominal segments. These structures 

 furnished sufficient points for the differentiation of genera. In dealing with species, 

 however, we have had to have resource to other characters in order to distinguish 

 even the small number of pupae discussed, and it is probable that when further 

 materials are available the setae on all or most of the abdominal segments and every 

 other structure capable of giving assistance will have to be included in devising 

 a complete scheme of classification. 



Table of Tribes. 



1. Paddles small, breadth less than half the diameter of the 8th 



segment ; tufts on the 8th segment as long as the paddles 



or nearly as long . . . . . . . . . . . . Sabethini. 



Paddles relatively large ; tufts on the 8th segment shorter 

 than the paddles . . . . . . . . . . . . . . . . 2 



2. Large species ; long dorsal serrated hairs on the 7th and 8th 



segments . . . . . . . . . . . . . . . . Megarhinini. 



Smaller species ; without such long hairs . . . . . . . . . . 3 



3. Dendritic seta on the posterior angle of the 8th segment . . Anophelini. 

 Tuft or differentiated seta on the posterior angle of the 8th 



segment . . . . . . . . . . . . . . . . Culicini. 



The only species belonging to the tribe Megarhinini the pupa of which has 

 been described is Toxorhynchites brevipalpis, which has been figured by Bacot. 

 The large size of the pupa is at present sufficient to differentiate it from any other, 

 but the insignificant size of the tuft on the 8th segment, the absence of terminal 

 setae on the paddles, and the presence of long serrated dorsal setae on the 7th and 

 8th segments are also characteristic. 



