350 NATURAL ARRANGEMENT OF INSECTS. 



no question that in some years, in which they have 

 acquired excessive prolificness, they may make de- 

 structive excursions. All hooks on entomology are 

 redundant with its history : we shall, therefore, on ac- 

 count of our limited space, proceed to the Blattinai, 

 which, probably, would more properly come into our 

 third family. These are distinguished by their elytra 

 lapping one over the other, and being entirely coriaceous, 

 beneath which the wings are folded longitudinally: their 

 antennae are setaceous, and their legs all cursorial, with 

 pentamerous tarsi. Some genera, as usual, are entirely 

 apterous, at least, winged individuals have not yet been 

 seen belonging to them ; and this is the case in the New 

 Holland Polyzosteria, one of the largest insects of 

 the sub-family, and which is of a bronzy metallic tint. 

 In Perysphceria and Heterogamia, the male is winged, 

 and the female apterous. The majority, however, are 

 winged insects in their final condition. They are lu- 

 cifugous, and feed chiefly at night. Commerce has 

 introduced many species to our sea-ports, some of which 

 have gradually spread all over the country; two of 

 which especially, the common black beetles, the Peri- 

 planeta Americana and Orientalis, are found in kitchens 

 and warm cupboards where provisions are kept : when 

 at large, they generally occur in obscure places or be- 

 neath stones, and sally forth, after night-fall, in search 

 of their prey. They are usually of a bright or dark brown 

 colour: some are livid or testaceous, as, for instance, 

 Blabera gigantea, which is the largest in the circle; and 

 a few are gaily coloured, as in Corydia and Phoraspis. 

 We find at large, in our woods, and beneath stones, the 

 Blatta Laponica and Germanica. The remarkable cap- 

 sule which contains their eggs, is a phenomenon oc- 

 curring no where else in the insect world, as it is formed 

 within the abdomen of the female : it is an oblong, 

 flattened brown sheath, within which the eggs are de- 

 posited in two rows ; and the female carries this attached 

 to her abdomen until the eggs are nearly mature, when 

 she lets it fall, and the compressed edge bursts open, 



