i8fi7.j 227 
Wings large, much longer than the abdomen (excepting in the micropteroua 
forms), membranous, the anterior pair dilated and rounded or elliptical at the 
apex. The nervures strong, arranged as follow : parallel with the costa runs a 
strong nervure, the radius; before its termination this more or less gradually 
recedes from the margin, forming a triangular or elongated space, generally darker 
colom-ed than the rest of the wing, and termed the pterostigma ; but immediately 
at the point where it recedes, it omits a short transverse vein to the costal margin. 
The subcosta is rudimentaiy, forming a fine vein at the base between the costa and 
radius, and scarcely visible without the aid of the microscope.* Below the radius 
runs a nervure which I here term the forked vein ; rather before the middle of the 
wing this vein divides, one branch running obliquely to the posterior margin ; at 
about the middle it divides again, one branch running to the costal portion of the 
apical margin beyond the pterostigma, and ending in a long and usually curved 
furcation ; the other branch runs into the apex, and emits two or three smaller 
branches to the dorsal portion of the apical margin ; the upper branch of the 
forked vein sends out one, and sometimes two (StenopcosusJ transverse veins to 
the radius. The first lower branch of the forked vein, after reaching the dorsal 
margin, frequently sends out a veinlet obliquely upwards, reaching the second 
lower branch, closing a large space which is called the discoidal cell (Psocus and 
Stenoiosocus) ; or this veinlet does not reach the second lower branch, but is directed 
back again to the dorsal margin, forming a free elliptical cellule (Ccecilius and 
Elipsocus) ; or this veinlet is absent (Peripsocus). The other nervures are 
xmimportant, consisting of a very fine vein, which may be called the cubitus, running 
obliquely from the base of the forked vein to the dorsal margin, and, within this, a 
stronger vein, I'unning nearly parallel with thedorsal margin, andwhich maybe called 
the post-costa. The posterior wings are shorter and narrower than the anterior ; 
the costal margin nearly straight, the apex obtuse. The neuration of these wings 
is veiy simple. The sub-costa is absent ; the radius joins the costa rather beyond 
the middle ; the forked vein first sends out a simple branch to the posterior margin, 
it then again forks, the upper branch dividing at the end, and enclosing a triangular 
cellule, the lower simple ; one transverse vein unites the forked vein to the radius. 
There is also a cubital vein running parallel with the first lower branch of the forked 
vein, and a rudimentary post-costal nervure. 
(The nomenclature of nervures is a subject on which scarcely two authors 
agree. That here given will bo found suSicient for all purposes connected with 
British species. A. reference to the plate will render this terminology better 
understood.) 
The eggs are laid iu patches on leaves, bark, or other objects, and 
the females cover them with a web. The larvae and pupas greatly re- 
semble the perfect insects. As in all Pseudo-Neuroptera, the line of 
distinction between the larva and pupa states is not evident, the changes 
being very gradual ; the more fully developed individuals bearing rudi- 
mentary wing sheaths. The ocelli in these states are absent. The 
* In the " KntomoIoKist's Annual," 1861, p. 18, Hagen calls the vein forming the ptei-ostigma, the 
" sub-costa," and he terms the forked vein below this the "radius." I consider the sub-costa to be 
certainly represented by the rudimentary vein described above. 
