ELACHISTA, 249 
ened); in the posterior wings the median and discoidal veins are dis- 
tinct. 
From the variation in the neuration of the anterior wings, as 
above mentioned, it is extremely probable that, natural as this 
genus at first sight appears, it may hereafter be capable of sub- 
division. The perfect insects are not unfrequently met with in 
little swarms, being actively on the wing during the afternoon or 
evening ; when at rest they sit very closely appressed to the leaf, 
blade of glass, or other substance on which they happen to repose, 
and appear perfectly sluggish; but the moment the collector in 
attempting to catch the inert specimen agitates the foliage, or 
breathes too roughly on its resting-place, quickly the antenne, 
which had lain couchant by the side of the insect, start forward, 
are briskly agitated, and the insect, now completely roused from 
its seeming torpor, runs forward, spreads its wings, and is—gone. 
“We think we have it, but yet we have it not.” Most of the 
species appear to be double-brooded, appearing in May and Au- 
gust ; some, which we only meet with in June or July, have pro- 
bably only a single brood in the year; yet of the double-brooded 
species the August brood seems far less numerous than the May 
brood, which is no doubt owing to the perfect insects keeping 
themselves more concealed, as we have observed to be the ease in 
other late-appearing species. 
The fortunate discovery by Mr. Logan of the larva of one of 
the species, has already led to the discovery of a considerable 
number; no less than eighteen different larvee having been al- 
ready distinguished, several of which have been reared. From 
these we find that the habit of the larvae of this genus is to mine 
in the leaves, and down the stems of grass; but there is consider- 
able diversity in the mode of mining, some species remaining al- 
ways at the top of the leaf, others descending down the stem to- 
wards the root; in the mines of some species the leaf remains 
flat, in others it has an inflated or puckered appearance. The 
larvee of the May brood may be found throughout the winter and 
early spring; the larvae of those species which do not appear in 
the perfect state till June or July, may be met with in April and 
May; the larve of the August brood, feeding up at the end of 
June, are less easily observed, from the general luxuriance of ve- 
getation at the time. ‘The larva when full-fed quits the mine 
and changes to a naked, rather angulated pupa, on the stem or 
leaf of grass, or some neighbouring plant; a belt of silk is gene- 
rally placed round the middle of the pupa, which is also attached 
by its tail, but no outer covering of silk is made by any of the 
VOL, III. 2K 
