THE CANADIAN ENTOMOLOGIST. 387 



years, and beg to express my decided dissent from such a proposition. If 



a horse were clothed with scales as large as saucers, with no structural 



differences, it would not be tolerated as a distinct genus. But such 

 examples are hardly pertinent here. A graver charge is that Mr. 

 Theobald believes that palpal characters should not be used, because of 

 the difficulty of detection. In other words, we should not trouble 

 ourselves about natural or genetic characters when they are difficult to 

 observe, but use artificial ones that may be easily seen. However, he 

 urges that the palpal characters are not as t^rue indices of relationships as 

 are the scale characters. This is important if true, but I am bold enough 

 to say that it is not true. In all other families of Diptera the structure of 

 the palpi has been found safe in classification, and it would be strange 

 indeed if the mosquitoes should prove to be an exception. And Mr- 

 Theobald is hardly consistent \ he readily uses certain palpal characters 

 for the definition of subfamilies, but denies to others generic value. And 

 it must be remembered that Mr. Theobald bases his ideas of relationships 

 almost exclusively on scale characters, and it is no wonder that he reasons 

 in a circle. My own conclusion is that characters derived from the shape 

 of the scales are both artificial and inconvenient, and at most only of 

 specific value. 



The proposal of a host of genera based upon such trivial characters 

 is bad enough, but words fail me in my expression of amazement at the 

 proposition to base a dozen or more subfamilies almost wholly upon 

 secondary sexual and scale characters. Secondary sexual characters are 

 looked upon universally by taxonomists as of very doubtful generic value, 

 and very rarely have they been accepted. Here we would have them do 

 duty as primary divisional characters in the family. Theobald naively 

 says that the males of his Toxorhynchitinae can not be distinguished from 

 the males of his Megarhininae, even generically. " The females of the 

 Culicinae and /Edomyinse are so alike that, without the examination of the 

 males, it is not always possible to place them in the right subfamily.'' 

 Coquillett, who has tried to avoid secondary sexual characters in his 

 definition of the subfamilies, separates, for example, his Psorophorinse and 

 Culicinae, as follows : 



'•' Femora bearing many outstanding scales ; wing scales 



narrow Psorophorinse. 



'■ Femora devoid of outstanding scales (except in the genus ^dof?iyia. 

 which has broad wing scales) Culicinae." 



