91 



Place nymphae in drops of water on a slide 

 and examine the air syphons. Note — 



I. In Anophelines the syphons have a square 

 truncated end, and are proportionally much shorter 

 than in Culex, and project from about the middle 

 of the thorax (Figs. 24 and 25). 



. CvlcK. 



i,S{io o'M/iq. 



1''"p«- 3. ;«h,,.»-/ty>,ci:S \.an'/M-<. 



ti^JtuLy^^tyykf*^ t Hi 



Fig. 25. Nymphal Syphon Tubes 



2. In Culex the syphons are long and narrow, 

 and have a sht-like opening, and project from the 

 posterior portion of the thorax (Figs. 24 and 25), 



