ORTHOPTERA. 



185 



are of a more membranous texture, and, in a state of rest, are folded longitudinally, 

 and almost entirely covered by the elytra. The abdomen is broad and flat, and 

 carries two jointed appendages — the cerci — near its extremity. About six 

 species are found in Britain, of which three only are really indigenous, the 

 others having been imported. The common cockroach (Periplaneta orientalis) 

 is believed to have belonged originally to the East, though now found in almost 



egg-case of the common kitchen cockroach (the top figure nat. size, the others much enlarged). 



all parts of the world. These insects are commonly spoken of as " black-beetles," 

 though not beetles, and not black, but having a reddish brown colour. The male is 

 easily recognised by the wings, of which there are two pairs, scarcely reaching 

 beyond the middle of the abdomen. The female is broader in the body, and has 

 very short rudimentary fore-wings and no hind-wings. Her eggs are arranged in 

 a horny case, opening at the top, and shaped like a purse, which she carries about 

 with her for some time, protruding from the end of her abdomen. She finally 

 deposits the egg-capsule in a crevice in the walls or below the floor, and after some 

 interval the young larvae are excluded. During growth they shed their skin several 

 times. The new skin is at first soft and of a pale or nearly white colour, but 



1 2 



cockroaches. 

 1, Phyllodromia germanica, male and female ; 2, Ectobia lapponica. (Nat. size.) 



gradually hardens and gets darker. The American cockroach (P. americana) 

 which is such a pest on many ships, and is found about the docks and ware- 

 houses of seaport towns, is larger than the common species. Although it 

 somewhat resembles the latter in general colour, it has two pale bands on the 

 prothorax, and is winged in both sexes. The German cockroach (Phyllodromia 



