ANNETTE F. BRAUN 
1.59 
genera, tl\ese structures though modified have not entirely lost 
their spine-like character (Fig. 4). Even where modified, they 
may be distinguished fi’om the rest of the scale covering of the 
hind wing b}' the fact that the}' are thicker, yellowish, more 
heavily chitinized structures. Instead of projecting forward, 
they extend oblicpiely backward, lying flat on the surface of the 
wing. In some species of Nepticida, these spines become greatly 
elongated, forming a flattened bunch of hairs lying on the wing 
within the costa (Fig. 2). 
A feature common to all the genera is the presence of bristles on 
the upper side of the posterior tibiae. The position of the middle 
spurs of the posterior tibiae — whether situated in the middle, 
or above or below the middle — is a generic character. 
With the exception of several gall-making species of Ectoedemia, . . 
the larvae of all species of which the life history is known, are 
miners within the tissues of leaves (rarely in fruits) or in bark. 
They show a preference for trees and shrubs, but not a few mine 
leaves of herbaceous plants. When full grown, the larva, with 
few exceptions, leaves the mine and dropping to the ground, spins 
a dense flattened cocoon amongst the rubbish or in the loose sur- 
face soil. 
The egg is a minute oval body attached to the surface of the 
leaf or bark by a minute glistening speck of cement, which ren- 
ders its location visible even to the naked eye. 
The lorva of Nepticida upon hatching eats directly into the leaf, 
and makes a very narrow linear mine, which is at first often 
difficult to discern, since in its early stages, the larva consumes 
but a small part of the leaf tissue. This mine may continue as a 
linear mine, gradually broadening throughout its course, or it may 
at some period abrupth' enlarge into a blotch. In the latter 
portions the mine is semitransparent and easily visible. The 
mine of any one species is very constant and characteristic in 
appearance, and in most instances serves for immediate identifica- 
tion of the species. The species of Ectoedemia are gall-producers 
or bark-miners in forest trees. 
The larva is slightly flattened, with head deeply retracted into 
the prothorax, due to the lengthening of the dorsal side of the 
head. For the details of head structure, the reader is referred to 
TRAXS. AM. EXT. SOC., XLIII. 
