156 
NORTH AMERICAN NEPTICULIDAE 
outward to radius just beyond R2+3, aod anastomosing with 
radius to beyond middle of wing, as before, or remaining separate 
from radius, in which case ( Trifurcula) H44-5 is ahsent. R2+3 co- 
incident. R4+5 separating beyond ■\I, or coalescing to apex. 
Cubitus unbranched, sometimes coincident with M or becoming 
obsolete beyond its point of separation from ]\I. Fecond anal 
vein very prominent. Cross veins absent. A juguni is present 
in females of the more primitive genera. 
Hind wings (Figs. 1 to 6). — Subcosta and Ri coincident; Rg 
and M coalescing to about the middle of the wing. Media one 
or two branched. Culatus unbranched. No cross veins. Fren- 
ulum of male consisting of a single strong spine; of female rudi- 
mentary, of several minute spines. The function of the frenulum 
is performed in the female liy a series of curved spines along base 
of costa. One-half to almost as broad as the fore wings. ^ 
Fore icings . — lb very prominent, simple at base; 2 often becoming ob- 
solete; 3 absent, veins present between 4 and 8 seeming to arise from one 
stalk; stalk apparently arising from lower median or from upper median be- 
yond 10, sometimes connected with lower median just beyond 10. 9 absent. 
Hind wings . — 3 and 4 absent; cell open between 2 and .5+6. 
A striking and unique characteristic of the family is the entire 
absence of true cross veins. That the apparent cross vein present 
in some genera, passing obliquely from cubitus to radius just 
beyond R2+3 is in fact a portion of media, is shown by studies 
on the tracheae of pupal wings published elsewhere, and by the 
occasional persistence in the imago of the tracheae which pre- 
cede the wing veins. 
Discussion of the origin and phylogenetic relationships of the 
family is reserved until a more complete account of the structure 
of the various parts is given. 
The head is rough tufted, both on the face and crown. This 
tuft is composed of irregular hair-like scales, usually of a color 
contrasting with the eye-caps and with the rest of the liody. 
Behind the tuft and eyes, the scales form a pair of flap-like 
structures, usually Ijdng flat, but sometimes erected in dead 
'Owing to the fact that in the greater part of the published work on IMicro- 
lepidoptera the Comstock-Needham system of vein nomenclature has not been 
used, the following characterization of the venation is given for purposes of 
convenience. 
