NEUROPTERA. 63 
larger than the others, called from their form furban’d or columnar 
‘ eyes. The junction having been effected, the couples place them- 
selves on trees or plants to complete their-coitus, which lasts but for 
amoment. The female soon after deposits all her eggs in the water, 
collected i in a bundle. . 
The. propagation of their speciés is the only function these animals 
have to fulfil, for they take no nourishment, and frequently die on 
the day of their metamorphosis, or even within afew hours after 
that event. Those which fall into the water become food for Fishes, — 
cand are styled: Manna by fishermen. © ' 
If however we trace them back to that period in which they ex- 
isted as larve, we find their career to be much longer, extending 
from two to three years. In this state, as well as that of semi- nymphs, 
they live in water, frequently concealed, at least: during the day, in 
the mud or under stones, sometimes in horizontal holes divided in- 
teriorly into two united canals, each with its proper‘opening. These 
habitations are always excavated in clay, bathed by water, which oc- 
cupies its cavities; it is even supposed that the larve feed on this earth. 
Although allied to the perfect Insect, when it has undergone its 
ultimate metamorphosis, in some respects they differ. The antennze 
are longer#the ocelli are wanting; and the mouth presents two 
_ projections resembling horns, which are considered as mandibles. 
On each side of the abdomen ‘isa range of laminz or leaflets, usually 
“united at base by pairs, which dre a sort of pseudo- branchiz over 
which the trachez extend and ramify, and which not only enable 
them to respire but’also to swim and move with greater facility’ the 
tarsi have but one hook at their extremity. The posterior extremity 
of the body is terminated by the same nysnbep of setz as that of the 
perfect Insect. f 
_ The'seminymph only differs from the pthe in the presence of the 
__ cases which enclose-the wings. When the moment of their deve- 
lopment has arrived, it leaves the water, and having changed its 
' skin, appears under a new form—but, by a very-singular exception, 
it has still to exper ience a second change of tegument, before it is 
prepared to’ propagate its species. The ultimate exuvium of these 
Insects is frequently found on trees and walls; they sometimes even 
leave them on the Clothes of persons who may be walking in their 
vicinity. 
With this genus ad that t af the Bhns panes: De Geer ea an 
order founded on the absence or extreme exiguity of ‘the mandibles. 
In the “¢ Tableau Elémentaire de |’Histoire Naturelle des Animaux” 
of the Baron Cuvier, they also constitute a separate family, that of 
the Agnathes, but still forming part of the’order of the Neuroptera. 
