GENERIC CHARACTERS OF LARV^ OF CULICIDiE 59 



is almost white, and this Hghter coloration persists longer 

 on the head and anal tube than elsewhere, so that the 

 newly-dressed larva presents quite a distinctive appearance. 



In many points these larvse are intermediate in form 

 between those of Culex and Corethra, but the head is most 

 like that of Anopheles, forming like it a truncated cone, but 

 differing in being pinched in in front of the eyes, so as to 

 present a pyriform outline ; and seen from the side the 

 difference is even greater, as the tergal plate of the second 

 metamere is bent downwards and then backwards, so that 

 the anterior part of the clypeus overhangs the mouth. The 

 tergum of the third metamere is cordate, being deeply in- 

 curved in front for the reception of the hinder part of the 

 clypeus. The eyes are placed well back on the broadest 

 part of the head, and are of oval form, with the long 

 diameter transverse. The antennas consist of a single 

 joint, are moderately long and thick, and when at rest are 

 directed downwards so as to be scarcely visible from above : 

 they are provided with several jointed bristles, some of 

 which are longer than the antennae itself. The labrum is 

 almost rudimentar}'. 



The mandibles are strong and trenchant, and in addi- 

 tion to their teeth, carr}^ a variety of simple and compound 

 hairs, some of which are of very specialised forms. The 

 maxillae are short broad plates, with a sinuous anterior 

 border and stumpy, conical palps. They and the lower 

 lip, in addition to ordinary hairs, are provided with several 

 ranks of peculiar flattened bristles with truncated dentate 

 ends. 



On the maxilla, the inner face of the external sinuosity 

 is provided with a single row of these peculiar plates, 

 but on the labrum, which is transversely oval, there are 

 three, and on the lateral plate of the metamere, with 

 which the maxilla articulates, no less than five ranks of 

 different lengths. They look as if they were designed to act 

 as a sort of sieve to exclude too coarse materials from the 

 mouth, but, as the larva is predatory and subsists mainly 

 on small crustaceans, they are more probably retentive 

 organs. The thorax is relatively very large, somewhat 



