644 EXTERNAL ANATOMY OF INSECTS. 
than the rest, which is also to be found in many others 
of the Muscida, some of which have two and others more 
of these spurs. The little moth-like midges (Psychoda) 
at first appear to have the whole surface of their wings 
covered with hairs; but upon a closer examination it 
will be seen that they are planted in the nervures, from 
each of which they diverge, so as under a lens to give it 
a very elegant appearance*. This fly has its wings 
beautifully fringed with fine hairs, the thzrd circumstance 
to be attended to under this head; in the Tipulidans, 
and many others of this Order, the apex and posterior 
margin are also finely fringed with short hairs. Some 
Dipterous insects make a near approach to the Lepido- 
ptera in the covering of their wings: in the common gnat, 
when the wings are not rubbed, the nervures are adorned 
by a double series of scales, and the marginal fringe also 
consists of them”; and in a Georgian genus, which ap- 
pears in some degree to connect Culex with Anthraz, &c., 
there are scales scattered upon the membrane as well as 
upon the nervures ; besides, its antenne ° and abdomen 
are also covered with them. 
The Order, the clothing of whose organs of flight 
excites the admiration of the most incurious beholder, is 
that to which the excursive butterfly belongs, the Lepz- 
doptera. ‘The gorgeous wings of these universal favour- 
ites, as well as those of the hawk-moths and moths, owe 
all their beauty, not to the substance of which they are 
composed, but to an infinite number of little plumes or 
scales so thickly planted in their upper and under sur- 
° Prate X. Fie. 13. > Reaum. iv, ¢. xxxix. f. 4—11. 
° A portion of the antenna of the insect here mentioned is figured 
Prate XII. Fie. 23. 
