294 
gent muscles are running to the organ serving to push it forward 
and to retract it. Its appearance differs a little within the diffe- 
rent Culex-larvæ. 
Så 
Fig. 16. Horizontal se 
2 Å 
-3, Three sagittal sections through the head of the larva. 1 und 3 left 
ind rig id, to the median line; 2 in the median line: a maxilla; b diese 67 
labrum with mentum : g and c Morse e salivary duct ; Fekankeee to the pharyns. 
In collaboration with the hypopharynæ, the epipharyn% gards 
the entrance to the pharynæ (fig. 17 f). Immediately behind the 
organ described above is an almost flat plate-shaped part, perforated 
by the salivary duct (fig. 17e). It is this part which is commonly de- 
