﻿4 F. W. EDWARDS — A SYNOPSIS OF THE SPECIES OF 



American species, arrived at the conclusion that the length of the palpi is only 

 of minor importance, and that long (or, as they consider, short) male palpi have 

 been developed independently in different groups. After examining all the 

 material in the British Museum in the light of these views — which I much regret 

 I had not done before publishing any synoptic work — I feel bound to agree with 

 the American authors. They, however, go further, and refuse to recognise even 

 generic value in the differences of the palpi, since in most cases these are confined 

 to one sex. Although there is a great deal to be said for this view, it has not 

 been followed in the present paper, and hence it should be remembered that some 

 groups which are here given generic rank, would by some authors be regarded 

 only as subgenera, even if recognised at all. Scale characters have practically 

 been discarded as of value for generic definition, though it is true that groups of 

 species frequently show the same type of ornamentation in all their members. 



Coquillett (Science, xxiii, p. 312, 1906) divided the old genus Culex into two 

 groups, according to whether the claws are simple or toothed in the female, and 

 whether the eggs are laid singly or in masses. These characters are in most 

 cases correlated, and the mode of egg-laying is correlated with a definite 

 structure of the abdomen. No doubt there are a few forms which would be 

 difficult to place, but by far the larger number of Culicini fall into one of two 

 groups, which seem to be quite natural : — 



(1.) Aedes group. Eggs laid singly ; last segment of female abdomen narrow, 

 usually completely retractile into the penultimate ; claws of female, at least on 

 the four anterior legs, nearly always toothed. Genera : Mucidus, Psorophora, 

 Janthinosoma, Ochlerotatus, Stegomyia, Aedes, etc. 



(2.) Culex group. Eggs laid in masses ; last segment of female abdomen broad, 

 immovable ; claws of female never toothed. Genera : Culex, Taeniorhynchus, 

 Aedomyia, Theobaldia, Uranotaenia, etc. 



This division of: the tribe is much more natural than one based on the length 

 of the palpi ; it will be seen that forms with short male palpi are included in 

 both groups. 



Table of Genera. 



1. Claws of female toothed ... ... ... ... ... ... 2. 



Claws of female simple ... ... ... ... ... ... 5. 



2. Posterior cross-vein slightly beyond mid cross-vein ; legs shaggily 



scaled ; female palpi half as long as proboscis ... Mucidus, p. 6. 

 Posterior cross-vein before mid cross-vein ; legs not shaggily 



scaled, female palpi not half as long as proboscis ... ... 3. 



3. Male palpi with two apparent joints ; thorax bright yellow at the 



sides ... ... ... ... ... ... Banksinella, p. 6. 



Male palpi with three apparent joints ; thorax not bright yellow 



at sides ... ... ... ... ... ... ... ... 4. 



4. Last two joints of male palpi thin, about equal in length ; black 



and white species ; head all flat-scaled ... ... Stegomyia, p. 7. 



Last two joints of male palpi more or less thickened, especially the 

 penultimate, which is longer than the terminal ; not usually black 

 and white species, head not usually flat-scaled above 



OCHLEROTATUS, p. 14. 



