DESCRIPTION OF THE DERMATOPTERA. 289 
Tlio following is the succession of orders, placing the lowest upper- 
most : 
Dermatoptera Burm. 
Orthoptera Linn. 
Psvudoncuroptcra Erichson . 
Neuroptera Liuu., restricted by Erichson. 
Before discussing the relative standing of these orders, we will briefly 
indicate the more salient and generally applicable differential charac- 
ters, especially what we regard as the more fundamental ones, but 
slightly touching upon the mouth-parts and wings, these being peri- 
pheral and more adaptive characters and liable to greatest variation, 
and being of less value in characterizing the orders of Phyloptera. 
Order 1 . DERMATOPTERA. 
Forficula presents so many features separating it from the Ortho- 
ptera, and is so composite a form, that it should be regarded as the type 
of a distinct order, in which it was originally placed by Leach, Kirby, 
Bnrmeister, and Westwood. Its composite nature is seen both in the 
elytra ami the hind wings, which anticipate the Coleopterous type of 
wings. On the other hand the larva resembles Japyx, the Thysauuran, 
with its anal forceps, and in most respects Forficula is the lowest, 
most decided stem -form of the Phyloptera. 
The Dermatoptera are characterized by the flatness of the body, and 
the large terminal forceps. The head is flat, horizontal in position, 
while the presence of the V-shaped epicranial suture is a sign of inferi- 
ority, as it is characteristic of Thvsauura and Platypteran larvae as well 
as Coleopterous larvae. The remarkable thoracic structure, which is 
described farther on, as well as the curious overlapping of the abdom- 
inal tergites, forbid our uniting the Dermatoptera with the Orthoptera. 
1 he small, short elytra, and the very largo, rounded, longitudinally and 
once-cross-folded hind wings, which remind us rather of the Coleoptera 
than Orthoptera, are also important diagnostic features. Finally, the 
metamorphosis ot the Dermatoptera is eveu less complete than that of 
the Orthoptera. 
T he ligula ( PI. XXIII, Fig. G) is bifid, being divided into a pair of two- 
jointed paraglossse. The labium is' thus similar to that of the Ortho- 
ptera, though scarcely more like them than like Termes. 
Order 2. ORTHOPTERA. 
The head is more or less vertical in position; the front is very large, 
broad, and long, the epicranial region very large and often hypertrophied, 
the clypeus is large and subdivided as in Pseudouenroptera. In the 
Orthoptera, as a rule, the deeply-cleft ligula is indistinctly tour lolied, 
the outer pair ot paraglossaj very well developed, while the inner pair 
is minute or undeveloped, as in the Acrydii, especially Caloptenus; 
19 E 0 
