Scale Structure 



enclosed between the various veins, but for our present purpose 

 they need not be mentioned. The posterior margin of the wing is 

 always fringed with long scales, " the wing fringe." 



No account of the characters of mosquitoes would be complete 

 without some remarks on scale structure, the importance of which 

 has been very ably demonstrated by Mr. Theobald.* 



Head scales. Some or all of the following forms of scales may 

 be found on the head of a mosquito : 



1. ''Upright forked scales" (fig. 3, 2) are found chiefly 



towards the nape. These scales have long stalks with 

 an expanded fan -like head, the angles of which project 

 outwards like the prongs of a fork. They stand out 

 from the surface upon which they are inserted. 



2. " Narrow curved scales" (fig. 3, 3, are long curved 



scales tapering to their extremities ; the body of the 

 scale is expanded at its widest part to from ^ to ^ of 

 the length of the scale. These scales are chiefly found 

 projecting from the occiput. 



3. "Flat scales" (fig. 3,1) have a narrow pointed base; 



the body of the scale rapidly expands from the base. 

 The extremity of the scale is broad, with a flat or 

 slightly convex edge. These scales, in contrast to 

 the scales mentioned 

 above, lie closely 

 applied to the sur- 

 face from which 

 they arise and over- 

 lie one another like 

 the slates on a roof. 

 They are found on 

 the dorso-lateral 

 surface of the head. 

 Thoracic scales. Five forms of thoracic scales are described by 

 Mr. Theobald. 



1. Narrow hair-like curved scales ^fig. 3, 4) 



2. Narrow curved scales (fig. 3, 3 ). 



* "A monograph of the Oulicidae of the world" by Fred. V. Theobald, M.A., F.E.S., 

 British Museum (Natural History), Vols. I & II, 1901 ; Vol. Ill, 1903. 



Fig. 3. 



