POSITION AND TERMINOLOGY OF THE CULICIDyE 15 



It runs into the costa considerably before the tip of the 

 wing, and the relative position of this point is useful in 

 distinguishing species. The other of the anterior group 

 of veins is the first longitudinal, v^hich runs, without 

 branching, to join the costa, close to the tip of the wing. 

 From it, well out towards the middle of the wing, springs 

 the second longitudinal, which divides near the tip of 

 the wing into two branches, though in most Diptera 

 this vein remains single. Two veins spring also from 

 the second of the vein-trunk. These are the fourth and 

 fifth longitudinal veins and both of them become forked, 

 the fourth near the tip of the wing, and the fifth further 

 in. In the outer part of the wing, between the forked 

 second and fourth, may be seen the third longitudinal vein, 

 which is distinct, and fringed with scales only in this outer 

 part of the wing, and often appears to take its origin from 

 a cross vein ; but in many cases, as in C. concolor, R. Desv., 

 it can be distinctly traced as an unsealed vein right to the 

 root of the wing, and, in the majority of cases, can be so 

 followed for a considerable distance, while it is not uncommon 

 to find a short length of the vein, internal to the cross veins, 

 provided with scales. From the hindmost of the three 

 root-trunks there springs only a single scaled vein, the 

 sixth longitudinal, which runs without branching to end 

 in the internal margin of the wing beyond the middle. On 

 either side of this, however, is an unsealed vein, one of 

 which joins the tip of the hinder branch of the fifth 

 longitudinal, and is spoken of by Mr. Austen as the sixth 

 longitudinal (the sixth becoming his seventh), and the 

 other being his eighth longitudinal. 



As a rule, these unsealed veins are left unnoticed in 

 descriptions and figures of mosquitoes. 



We come now to the transverse veins or venulce, of which 

 there are four in the Cidicidce. 



Between the costa and auxiliary, close to the root of 

 the wing, is the humeral transverse ; and the spaces into 

 which it subdivides the interval between those veins are 

 known as the costal cells. 



Between the second and third longitudinals lies the 



