DESCRIPTION OF THE PSEUDONEUROPTERA. 291 
These characters, though superficial, are the most important yet pre- 
sented, perhaps (disregarding the metamorphosis), for separating the 
Pseudoneuroptera from the genuine Neuroptera. But the cleft labium 
is also to be found in Orthoptera; and among the Orthoptera, which 
usually have five-jointed tarsi, the Mantid® have four tarsal joints. The 
Perlid®, Odonata, and Ephemerina have been, by Gerstiicker (Peters 
and Cams’ Zoologie), associated with the Orthoptera under the name 
Orthoptera amphibiotica, but such an alliance does not seem to us to be 
entirely a natural or convenient one ; it is simply transferring a mass 
of heterogeueous forms to what, as now limited, is a natural and well 
circumscribed category, and yet we confess that it is difficult to give 
diagnostic adult characters separating the Pseudoneuroptera from the 
Orthoptera, though the general facies of the Orthoptera is quite unlike 
that of the the Pseudoneuroptera. 
In the Pseudoneuroptera, beginning with the more generalized forms, 
the Perlid® and Termitid®, the labium (second maxilhc) is deeply cleft, 
the cleft not, however, iu these or any other insects, extending to the 
rnentum. or even clear through the palpiger. Each lobe is also cleft, 
so that the ligula is really four-lobed ; the outer lobes are called by 
Gerstiicker 130 the “lamina externa,” and the inuer the “lamina interna.” 
These fiuger-shaped, non-articulated, fleshy lobes appear to be homolo- 
gous with, or at least suggest the outer pair of, paragloss® of the Cole- 
optera and Hymenoptera. In the Perlid® (PI. XL, fig. 6) the four 
lobes of the ligula are well developed, and the lobes of the inner pair 
are broader than the outer. In the .Termitid® (PI. XLI, figs. 2, 3) the 
lobes are well developed, but the inuer pair of lobes is either one-half 
or not quite so wide as the outer paragloss® ; the palpiger is cleft. In 
the Embid®, according to Savigny’s figures, the ligula is four-lobed, but 
the inuer pair is narrow and rudimentary. 
Iu the Odonata, according to Gerstiicker’s excellent drawings, the 
ligula varies much. In Gomplius it is entire; in some of the higher 
Libellulin® only two-lobed; but in iEschna it is four-lobed, the outer 
lobe slender, but separate from the palpus. In Calopteryx the ligula is 
widely cleft, the two inner lobes are wide apart, while the outer pair 
is consolidated with the labial palpi. Owing to the specialized nature 
of the labial palpi, the mouth-parts of the Odonata are sufficiently sui 
generis and distinctive to prevent their being placed among the Ortho- 
ptera, even if the thorax were not so dissimilar. In the aborted labium 
and other mouth-parts of the Ephemerina we also have strongly-marked 
characteristics forbidding their being placed in the Orthoptera; were it 
not for the strong resemblance of the Termitid® to the Orthoptera 
(Blattariro,) probably no one would have thought of carrying the Pseudo- 
neuroptera over into the Orthoptera. 
The relative proportion of the headiand sclerites varies greatly; no 
189 Zur Morphologic tier Orthoptera amphibiotica. Aus tier Foatachiift zur GeaeUach. Natur 
torach. Froumle, 1873. 
