OR THOPTERA. 
1S3 
and feed upon leaves. Most inhabit tropical and subtropical countries, and 
amongst them are some of the largest insects known, more than one measuring 
over 13 inches in length. Two species are found in South Europe, belonging to 
the genus Bacillus, and are both wingless forms of rather small size. One of these 
is figured in the illustration; and, as examples of some of the more finely-coloured 
tropical forms, two species from the island of Borneo are represented on the 
coloured Plate of Orthoptera. 
The leaf-insects, though belonging to the same family, exhibit a marked 
contrast to stick-insects in the shape of the body, which, instead of being narrow 
and cylindrical, is broad and flat. The male is narrower than the female, and 
distinguished also by having moderately long antennae, well-developed hind-wings, 
and short fore-wings. In the female the antennae are very short, the hind-wings 
ONE OF THE STICK-INSECTS OF SOUTH EUROPE (Bociilus TOSsi) AND ITS LARVA (nat. size). 
are rudimentary; and the elytra are fairly large, leaf-like structures, which, in 
some species, almost entirely cover the broad, flattened abdomen. The legs have 
broad, leaf-like expansions on both the femora and tibiae, contributing to the 
general leaf-like appearance. It is remarkable that the colour of these insects, 
which is either the green of a living leaf, or some shade of yellow or brown, like 
that of a withered leaf, is due to a substance similar in its nature to chlorophyll, 
or the green colouring matter of plants; and it is stated that the internal structure 
of the elytra bears a striking resemblance to that of a plant. All these curious 
insects belong to the single genus PhyUium, and are found in the Oriental countries, 
and in some islands of the Indian Ocean. 
The praying insects, or Mantidce, constituting the next family 
of the suborder, have the head turned down, with the face inclined 
backwards, so that the vertex projects in front, while the mouth lies close to the 
lower edge of the prothorax. They have many-jointed, bristle-like, or comb-like 
antennse. The prothorax is generally much longer than the other two segments 
of the thorax taken together; whereas the two hinder pairs of legs are long, and 
resemble one another. The fore-legs—which are inserted close to the front and 
wider end of the prothorax—exhibit a peculiar form and structure, their coxae 
being long and three-cornered, and often spined on the angles, and the femora broad, 
flattened, and grooved below to receive the tibiae, which can be folded back upon 
Praying Insects. 
