336 ZOOLOGY 



The insects grouped together in the order Orthoptera axe 

 all of a fair size, and compared with the beetles and flies are 

 comparatively few in number. They may be classified in 

 two groups : (i.) the Dermaptera, comprising the earwigs, and 

 (ii.) the Orthoptera genuina, which include the cockroaches, 

 grasshoppers, locusts, crickets, etc. 



1. Dermaptera. 



FoEFicuLiDAE. — This family consists of the earwigs, 

 the most familiar of which in our country is the genus 

 Forjkula. The body is elongated, the head flattened, with 

 filiform antennae, round eyes, and no ocelli. The prothorax 

 is free, the anterior wings short and horny ; the posterior, 

 which are folded longitudinally and transversely beneath them, 

 are membranous. The abdomen has nine segments, and termi- 

 nates in a pair of forcep-like processes which have been homo- 

 logised with the cerci anales of other forms. These insects 

 are nocturnal in their habits, concealing themselves in flowers 

 and fruit during the day. The female watches over her 

 young. 



The remaining groups of the Orthoptera — the Cursoria, 

 the Gressoria, and the Saltatoria — are usually grouped together 

 as the Orthoptera genuina. 



2. Orthoptera Genuina. 



I. CuKSOEiA. — This sub-order comprises the various species 

 of cockroach which are found all over the world. The body 

 of these insects is flat and oval, the pronotum is large, the 

 antennae long, the legs are adapted for running, and the 

 tarsus is five - jointed ; a pair of ringed cerci anales are 

 present. . 



There are about 800 species of cockroaches : some, as 

 for example Polyzosteria, are wingless ; others, as Reterogamia, 

 have the females wingless ; whilst Blatta {Phyllodromia) and 

 Periplaneta, the species found in Europe, bear wings in both 

 sexes, except P. orientalis, the female of which is wingless. 

 Cockroaches avoid the light, and are nocturnal in their habits 



