TILLYARD.—-Psocoptera, or Copeognatha, of New Zealand. 173 
and Needham. Having examined the tracheation of the wings in the last 
two instars of an Australian species of Psocus, I have been able to prove 
that this vein is from the very first a branch of Cu. This result brings the 
Psocoptera into line with all other insects, in which it is now known 
universally that the vena dividens, separating the clavus from the rest of 
the wing, is formed by Cu,. The only anal vein in the Psocoptera is the 
strongly convex 1A, running more or less close to the wing-margin. 
In the hindwing the venation is considerably simplified. Se is absent 
or a mere remnant, and there is no true pterostigma. Rs has two branches, 
as in the forewing, but M remains usually unbranched, though it may possess 
two branches in a few very archaic types. · Basally, R, M, and Cu, become 
united for a space, and more distally Rs and M again unite for a short 
distance. There is no cubital loop, Cu, remaining always unbranched and 
running obliquely to near the middle of the posterior margin. Cu, is 
unbranched, and 1A usually very short. 
The question of the affinity of the Psocoptera with other orders 
Little is known of the life-histories of the Psocoptera. Their eggs are 
laid in flat masses of twenty or more together, on leaves or under bark, 
and are covered with a fine protective web, spun from the mouth of the 
insect in a manner similar to that of the lepidopterous caterpillar. The 
young resemble the imago, except for the absence of wings; they have 
always two-jointed tarsi. The number of instars is not large, probably 
four only, the wing-buds appearing at the second instar. In the last instar 
the size of the body may appear even greater than that of the imago; but 
it shrinks somewhat just before the metamorphosis, which is accomplished 
with ease and celerity. 
CLASSIFICATION. 
The wiles is usually divided into two suborders on the number of 
joints in the tarsi, as follows :— 
..* Suborder TRIMERA. 
Suborder DrMERA. 
{ -known about them, that much more work remains to be done 
ee a ad cnt position to offer à classification of the order which 
t its main lines of evolution. ( 
ix. ipee contain seven families—the Amphientomidae, Lepidop- 
‘ Troctidae, Mesopsocidae, and Myopsocidae. 
Of these, only five have so far been found in New and—viz., the 
Lepidopsocidae, Atrop 
socidae, and Myopsocidae. 
