ORTHOPTERA. 



183 



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 antennas are very short, the hind-wings 



one of the stick-insects of south Europe (Bacillus rossi) 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 Phylliu7n, 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 

 antennae. 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. 



