Head Scales. (i) Narrow curved ; (2) upright 

 forked ; (3) flat and occasionally spindle or twisted 

 scales. 



In the sub-family Anophelina, examine the genus 

 Anopheles (e.g., A. maculipennis), note that it has 

 upright forked scales only on the head, and again the 

 genus Stethomyia (e.g., S. nimba), and note that it has 

 a median patch of flat scales on the head. 



In the sub-family Culicina examine the genus 

 Culex (e.g., Culex fatigans) and the genus Stegomyia 

 (e.g., Stegomyia calopus, v. fas data). Note that the scales 

 on the head are quite different in the two cases. All 

 mosquitoes belonging to the genus Culex have on the 

 head (i) narrow curved and (2) upright forked, but 

 only (3) a few flat scales laterally (Fig. 57) ; whereas 

 all mosquitoes belonging to the genus Stegomyia have 

 on the head (i) no narrow curved scales, (2) a few 

 upright forked, and (3) flat scales covering the whole 

 of the head|(Fig. 57). 



Cult*. 



Fig. 57. Head Scales of Stegomyia (left] and Culex (right} 



Although these two mosquitoes are obviously 

 distinct, yet many mosquitoes, whickat first sight seem 

 identical, are found to be quite different when their 

 scales are examined. 



