the Orders of Orthoptera and Neuroptera. 151 
forbidding their being placed in the Orthoptera; were it not 
for the strong resemblance of the Termitide to the Orthoptera 
(Blattariz), probably no one would have thought of carrying 
the Pseudoneuroptera over into the Orthoptera. 
The relative proportion of the head and sclerites varies 
greatly ; no general rule can be laid down as to the relative 
proportions of the epicranium and of the clypeus or of the 
gular region. 
On this account I had at one time decided to split the group 
into two, and to restrict Erichson’s Pseudoneuroptera to the 
Platyptera *, and to adopt Latreille’s term Subulicornia for 
the Odonata and Ephemerina (Subulicornes of Latreille). It 
may, however, be best for the sake of clearness to retain 
Erichson’s order Pseudoneuroptera as he indicated it, and to 
dismember it into what may be regarded, provisionally at 
least, as three suborders :— 
1. Platyptera (Termitidee, Embide, Psocide, and Perlidee 
=Corrodentia and Orthoptera amphibiotica in part). 
2. Odonata (Libellulide). 
3. Lphemerina (Kphemeride). 
It is comparatively easy to give well-grounded differential 
characters for these three suborders. They are so distinct 
that they may perhaps hereafter be regarded as entitled to the 
rank of orders, or the Pseudoneuroptera may be dismembered 
into the Pseudoneuroptera and Subulicornia (Odonata and 
Ephemerina). 
1. Platyptera.—The body is flattened; the head horizontal. 
The pronotum is large, broad, and square. The meso- and 
metanotum are remarkable on account of the imperfect 
differentiation of the scutum and scutellum; the latter is 
indefinite in outline, but very large. The flanks (pleurites) 
are, when long, oblique or are short. The sternites are 
usually very large and broad. There are often eleven uro- 
meres. 
2. Odonata.a—While the Odonata and Ephemerina are 
somewhat alike as regards the form and venation of the fore 
wings, in their mouth-parts and thorax they are entirely 
unlike. The Odonata are remarkable for the great dorsal 
(tergal) development of the mesepisterna and the enormous 
development of the meso- and metapleurites in general, while 
* This name (zAards, flat, wrepov, wing) is in allusion to the wings, 
which the majority (the Psocids folding their wings rather roof-like) fold 
flat on the back. The Isoptera of Brullé comprise the Termitide, 
