26 



3.3. Body elongcated. Head free. Pronotum elon- 

 gate. Legs slender, terete. Cerci articulate 

 or the joints scarcely distinct. Insect titted 

 for walking. 

 4. Forelegs raptorial. Cerci distinctly articu- 

 late. Mantodea. 

 4.4. Forelegs not raptorial, simple, mostly very 

 much elongated. Phasmodea. 

 l.l. Organs of flight inverted during the larval state. Hind- 

 femora fitted for leaping. Ovipositor free, corneous. 

 Organs of voice and sound-production present. 



Acridiodea, Locustodea, Gryllodea. 



General Characteristics. 



Form^ Size, Colour, &c. — The outline of the body throughout 

 the whole section of the Blattaria3 is very uniform, varying only 

 from ^ubhemispherical in Cassidodes to compressed elongate- oval, 

 the intermediate grades being the most common. In size the 

 adults vary from less than a quarter of an inch to about three 

 inches in length ; but the extreme sizes are comj^aratively rare. 

 The colours are usually sombre, mostly some shade of brown, 

 reddish, or yellowish, beside black ; l^luish, greenish, and metallic 

 tints, however, occur in the genus Polyzosteria. The markings, 

 when defined, are fairly constant as well as the general ground- 

 colour ; the eyes of the living insects are perhaps invariably 

 black, and the variations recorded by Walker are in the case of 

 Australian species scarcely anything else than the discolouration 

 produced by drying, putrescence, kc, or the effects of alcohol 

 and other chemicals. In the larval state the general colour is 

 often much paler and the markings much more definite and 

 decided than with the adults, although exhibiting the same 

 general type. 



Habits, Food, etc. — The habits of most species are nocturnal 

 or crepuscular, the remainder — sometimes all the species of large 

 genera — are entirely diurnal, notably of Apolyia and Polyzosteria 

 as limited by me. The majority appears to be wholly carnivorous, 

 their food consisting of other insects, eggs, larvae, kc, or their 

 dead bodies, even of their own kind ; the comparative im- 

 munity of our native shrubs, &c., from attack of injurious insects 

 is probably owing to a considerable extent to the silent hunting 

 of the formerly very numerous cockroaches, which, like the ants, 

 are not preyed upon by birds, on account of their disagreeable 

 scent. A smaller part, however, are decidedly less particular in 

 their diet, almost omnivorous, such as Perijolaneta orientalis and 

 P. americana. It is this minority which has brought discredit 

 upon the group, by making human habitations their almost ex- 



