i47 
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. fasciata). 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 (1) 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 (1) no narrow curved scales, (2) a few 
upright forked, and (3) flat scales covering the whole 
of the head (Fig. 57). 
Fig. 57. Head Scales of Stegomyia (left) and Culex (right) 
Although these two mosquitoes are obviously 
distinct, yet many mosquitoes, which at first sight seem 
identical, are found to be quite different when their 
scales are examined. 
