Orthoptera 



173 



hind the anal nervure, is much more extended in the 

 hindwing than in the forewing, and is the part which 

 undergoes fan-like folding when the wings are closed. 

 Though comparatively lowly insects, several families 

 of Orthoptera are distinguished by the possession of 

 complex sound-producing and hearing organs. All 

 members of the order are hatched in a form closely 

 like that of their parents. It has been estimated that 

 there are at least 10,000 species of Orthoptera which 

 are distributed among seven families (3, I07)> 



Hemimeridae. — The Hctnimcndj; form one of the smallest families 

 among insects ; only one genus, with two species, is icnown. 

 They are blind, wingless insects, somewhat lii^e Cockroaches, with 

 short, flattened legs and long cercopods. In the form of the head 

 and body, ho^vever, these insects resemble Earwigs, and it is possible 

 that they should be grouped with the Dermaptera rather than with 

 the Orthoptera. Their development is most peculiar; the eggs 

 are hatched within the body of the mother and the young are born 

 one at a time, after having grown to a considerable size. The two 

 species of Hcmhrn-rus inhabit West Africa. One of them is known 

 to live among the hairs of a large rat, and is believed to prey on 

 its external parasites (io8). 



V 



' 9 



Fig. 94. — Cockroach, P/iyllodi-omia geriiianica (Linn.) Europe, a. h. c. d. 

 successive stages of young ; e. male \ f. female expelling egg-case ; h. female 

 with spread wings, natural size ; g. egg-capsule, twice natural size. From 

 Riley, Insect Life, vol. 2 (U.S. Dept. Agr.). 



Blattidae. — The Blattida or Cockroaches are characterised by their 

 flattened form, and wide pronotum beneath which the head, carried 

 with the forehead downwards, is usually concealed. The coxa; of 



