150 Dr. A. 8. Packard, Jun., on the Classification of 
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 Mantide have four tarsal joints. 
The Perlide, Odonata, and Hphemerina have been by Ger- 
stiicker (Peters and Carus’s ‘ 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 hetero- 
geneous 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 Pseudoneu- 
roptera from the Orthoptera, though the general facies of the 
Orthoptera is quite unlike that of the Pseudoneuroptera. 
Inthe Pseudoneuroptera, beginning with the more generalized 
forms, the Perlides and 'Termitide, the labium (second max- 
ill) is deeply cleft, the cleft not, however, in these or any 
other insects, extending to the mentum, 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 * 
the ‘‘lamina externa,” and the inner the “ lamina interna.” 
These finger-shaped non-articulated fleshy lobes appear to be 
homologous with, or at least suggest, the outer pair of para- 
glosse of the Coleoptera and Hymenoptera. In the Perlide 
the four lobes of the ligula are well developed, and the lobes 
of the inner pair are broader than the outer. In the Termi- 
tide the lobes are well developed, but the inner pair of lobes 
is either one half or not quite so wide as the outer paraglosse ; 
the palpiger is cleft. In the Embidz, according to Savigny’s 
figures, the ligula is four-lobed, but the inner pair are narrow 
and rudimentary. é' 
In the Odonata, according to Gersticker’s excellent draw- 
ings, the ligula varies much. In Gomphus it is entire; in 
some of the higher Libelluline only two-lobed; but in 
Aischna 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 are con- 
solidated with the labial palpi. Owing to the specialized 
nature of the labial palpi, the mouth-parts of the Odonata are 
sufficiently sue generis and distinctive to prevent their being 
placed among the Orthoptera, 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 
* “ Zur Morphologie der Orthoptera amphibiotica,” Aus der Festschrift 
zur Gesellsch. naturforsch. Freunde, 1873, 
