ON THE CLASSIFICATION OF THE FAMILY 268 



are uniformly tinted to the end. In the first edition the 

 incompleteness of the original descriptions, which were all 

 that one had to go upon, led to great difficulties in com- 

 piling the tables, and large numbers of species had to 

 be relegated to special doubtful groups. In the present, 

 however, very few such instances remain, as with a few 

 exceptions, we have seen and handled all the species now 

 redescribed. 



The earlier entomologists framed their descriptions so as 

 to distinguish between the dozen or so of species alone 

 known to them, and probably in no way foresaw the 

 immense number that would be added by subsequent 

 observers. 



Hence, in all but a few species that are so common that 

 a sort of tradition as to their identity has been handed down, 

 there must always remain a doubt as to the identity of the 

 specimens subsequently referred to the names they gave, 

 and even in the case of that commonest of all species, Culex 

 pipiens, it does not appear to be by any means certain that 

 the species commonly so spoken of in England and Southern 

 Europe is really identical with the Scandinavian species 

 described by Linnaeus. 



Before proceeding to attempt to trace out a species of 

 the genus Culex, for example, the following points should 

 first be noted on a scrap of paper : — 



(1) Whether the wings are spotted or unspotted. If 

 spotted, the number and position of the spots, and whether 

 due to difference of colour or merely to local accumulations 

 of scales. 



(2) AVhether or not the tarsal joints are adorned with 

 lighter bands, and if so adorned, the exact position of the 

 markings. 



(3) Whether the thorax is adorned with markings, or 

 not conspicuously adorned. 



(4) Whether or not the abdomen is adorned with marks 

 or cross-bands, and if so, their character and position, 

 especially the relative position of lighter cross-marks on the 

 segments. 



With these points carefully noted, I hope that even the 



