76 SPOLIA ZEYLANICA. 
long. ‘The pterostigma is large, cell-like, not strongly chitinised (as 
it is in most Copeognatha), but thin-walled ; in the Echinopsocina 
it is a very long triangular cell projecting deep into the wing. 
Stigma sac at the basal part of the distal stretch of sc. In the 
genus Soa, Enderl. 1903, the subcosta (sc) is not divided into two 
parts, as in all the other Copeognatha ; a cross vein between the 
end of the proximal part of the subcosta and the stem of the 
radius effects the union (fig. 41). The pterostigma (branch 7,) is 
united with the peduncle of the radial fork by a cross vein, or 
fused with it over a certain extent; by this means a small 5-6 
angled cell is enclosed which is absent in Lepidopsocus and the 
Echinopsocine. In the Echinopsocina the radial ramus is not 
bifurcated but simple. Media triramous or biramous (Echinopsocus. 
Enderl., 1903). Radial stem in Lepidopsocus, Enderl., 1903, 
and the Echinopsocina strongly reduced in the basal portion, so 
that only one row of set or insertion-cupules indicate its course. 
Radial ramus constantly fused with the media over a greater or 
lesser extent. Areola postica long, peduncle usually short; cw, 
and cu, very long. Analis and axillaris never end at one point, 
but always separated from one another by an interval. 
In the hind wing the radial stem and the median stem coalesce 
(Lepidopsocine), or are only separated by .a long and extremely 
narrow cell (Perientominz). Radial ramus concrescent with the media 
- in the basal part, consequently 7, apparently arises from the media or 
radial ramus. Media with two quite separate branches. In the 
‘chinopsocine the hind wing is absent or only developed in miniature. 
Fore wing and hind wing with pronounced sharp and broad mar- 
ginal vein. Membrane of fore wing densely scaled; no delicate 
short hairs between the scales but only scattered very long stout 
hair-like scales. Veins and a narrow marginal zone of the fore wing 
with some stout seta (macrochete). The wing margin is beset 
with very long hairs which are inserted upon plug-shaped cupules 
which are closely arranged in numerous transverse series on the 
marginal veins. Hind wing entirely scaleless. At the border of 
the fore wing occur some moderately long spindle-shaped marginal 
scales whose edge in the apical half is finely spinose or serrate 
(fig. 51 rs). 
In the Perientomine the scales are strongly differentiated. 
Besides the slender fusiform sometimes more or less serrate mar- 
ginal scales in the dorsal half of the fore wing there are two 
forms of scales on the membrane of the fore wing, the one kind is 
much larger and relatively longer (COVER SCALES), the other smaller 
and relatively shorter (GROUND SCALES). The former are present — 
