EXPLANATION OF PLATE. 
Fig. 1. Wing of a gnat or 'mosquito {Gulex sp.), x about 16. 
1". Portion of 2nd longitudinal vein, greatly enlarged, 
to show the covering of flattened hairs and scales. 
I”. Portion of hind margin of wing, greatly enlarged, to 
show the fringe of scales. 
Fig. 2. The same wing denuded of hairs and scales, to 
show the course and nomenclature of the veins. 
C. costal vein (in Culicida) this runs right round the 
margin of the wing) : the anterior margin of 
of the wing is called the costa. 
1“, mediastinal vein. 
T, 1st longitudinal vein. 
II, 
2nd 
, issuing from the 1st. 
III, 
3rtl 
59 
, ,, ,. ,, 2nd. 
IV, 
4th 
55 
V, 
5th 
55 
VI, 
6th 
55 
VII, 
7th 
55 
VIII, 
8th 
55 
Tq anterior transverse vein, connecting the 3rd and 
4th longitudinal veins. 
T*'-, posterior transverse vein, connecting the 4th and 
5th longitudinal veins. 
It will be observed that the 2nd, 4th, and 5th veins are 
forked (the branch nearer the costa is spoken of as the 
upper, tl at nearer the hind margin of the wing as the 
loiver branch in each case), and that the sixth vein does 
not reach the margin of the wing. The relative lengths 
of the forks of the 2nd and 4th veins may vary in 
different species. 
Fig. 3. Wing of a midge (Chirommus pluinosus L.), 
X about 12, showing that the veins are destitute of flattened 
hairs and scales. 
1831— .500— 2/99 Wt 23575 D it S 9 
