14 



GNATS Olv MOSQUITOES — CHAPTER I 



has written on the CulicidcB, and, for our purposes it will 

 be best to confine ourselves to the wing of the mosquito 

 and the names that have been most commonly used by 

 those who have written on the family. 



Commencing with the anterior border of the wing, we 

 find tliat it is formed of a strong chitinous rib, which is 

 called the costa. It tapers off externally, but in the Gidi- 

 cid/e is continued round the entire border of the wing, 

 though this is not the case in all Diptern. 



m p 



Fig. 4. — Wing of C. coiicolor, R. Desv., S to illu.stratk thk 

 Terminology of the Wing in the Culicid^:. 



C, costa. 



a, auxiliary vein. 



1 to 6, first to sixth longitudinal 



veins and their branches. 

 7, seventh, or false longitudinal 



vein (unsealed). 

 VI, unsealed vein, between fifth 



and sixth longitudinals. 

 h, humeral transverse vein, 

 s, supernumerary transverse vein. 

 in, middle transverse vein. 

 2), posterior transverse vein. 



A, costal cells. 



B, sub-costal cell. 



c, marginal cell. 



D, anterior fork cell or first sub- 



marginal. 



E, second submarginal cell. 



F, first posterior cell. 



G, hinder fork cell, or second pos- 



terior. 

 IT, third posterior cell. 

 I, first basal coll. 

 J, second basal cell. 

 K, anal coll. 

 L, axillary cell. 

 M, spurious cell. 



Looking now at the root of the wing, we find that the 

 remaining longitudinal ribs, or veins, spring from three 

 main trunks, which are connected together near their base 

 by a somewhat elaborate arrangement of cross bars. From 

 the anterior of these spring two veins, the front one of 

 which is usually called the auxiliary vein ; on account of 

 its being absent in many Diptera, though Theobald calls 

 it the sub-costal and bv others it is termed the mediastinal. 



