158 
NORTH AMERICAN NEPTICULIDAE 
tionless spines. In the male, however, the frenulum is represented 
by a single strong spine (Figs, 2, 4 and 6) which hooks into a well- 
developed frenulum-hook. Near the base of the dorsal margin, 
best observed in the female of species of Ectoedemia (Fig. 3), is a 
structure which may lie interpreted as a jugum, vestigial in the 
males even of the more primitive genera, probably functional in 
females of Ectoedemia. 
Projecting from the wing membrane are. numerous minute 
curved pointed hairs, the “fixed hairs” or aculeae. These are 
most numerous on the underside of the fore wing, near the dor- 
sum. 
The scale-covering of the wings consists in general of the usual 
flat, striated, toothed scales, amongst which are scattered hair 
scales. In the more primitive species the scales are uniform in 
structure over the wing membrane, and are almost or ciuite 
lusterless. The tendency in such species is toward a general dull 
ocherous or drab color, without definitely defined markings. 
Later we find the fore wings with definite markings in the shape 
of fasciae and spots, which, in more specialized species, become 
sharply defined through the structural differentiation of the 
scales forming them, so that the wings are ornamented with 
metallic silvery, golden or bluish spots and fasciae; finally, the 
entire fore wing is clothed with these metallic scales. The cilia 
are composed of hair-like scales or of very attenuated scales of 
the striate toothed type — the latter occur most commonly in the 
costal and apical areas. 
In the males of some species, androconia are present, forming 
an oval opaque area on the upper side of the hind wing from tlie 
base to near the middle of the wing (shown in dotted outline on 
Figs. 2 and 6). Various other secondary sexual characters, in 
the nature of tufts of scales and hairs are present. The series of 
spines along the costal margin of the hind wing, which serve in 
the female to hold the two wings together, have in the male, with 
few exceptions, entirely lost their original function. In rare in- 
stances {e.g. N. rhamnicola) these spines have preserved in the 
male a structure and function identical with those in the female. 
In the earlier genera, and in the more primitive species of later 
