CULICID^E OR MOSQUITOES 



559 



As in all insects, they differ very materially in each species of one genus. Those 

 best known are the Anopheline eggs. 



The eggs always float on the surface of the water; immersion soon destroys 

 them, but many may occur in mud and can resist desiccation. 



FlG. 397. Types of scales, a to k ; head and scutellar ornamentation, I to 5 ; forms of 

 clypeus, 6. (Theobald.) i, head and scutellum of Stegomjia, etc.; 2, of Culex and 

 Mansonia ; 3, of Howardina, /Edes, etc. ; 4, of Megarhinus and Toxorhynchites, etc. ; 

 5, of Cellia and some other Anopheline.s ; 6, a', clypeus of Culex; b' ', of Stegomyia ; 

 f, of Joblotia. 



Characters of Adult Cuticida. The chief characters by which true mosquitoes, 

 or Culicidce, are known are the following : 



(i) Wings always with the veins covered with scales; the longitudinal veins, 



