INSECTA. 131 



FAMILY II. SALTATORIA. 



The pair of posterior legs remarkable for the size of the 

 thighs ; legs spiny and adapted to leaping ; males are en- 

 dowed with the faculty of making a stridulous noise, vul- 

 garly called their song ; sometimes they produce it by rub- 

 bing rapidly, one against the other, the interior surfaces of 

 their elytra ; sometimes they excite it by a similar alternate 

 action of the posterior thighs upon the elytra and wings, the 

 thighs acting like the bow of a violin. Three genera. 



GENUS I. GRYLLUS, Geoff. 



In the males a portion of the elytron, in the form of a mir- 

 ror or drum-head, forms the musical instrument ; elytra and 

 wings horizontal ; three joints to the tarsi. Two subgenera. 



SUBGENUS GRYLLO-TALPA, Lat. 



Tibia and tarsi of the two anterior legs wide, flat, indented 

 in the form of a hand and fit for digging. The female digs 

 for herself, in June or July, to the depth of six inches, a sub- 

 terranean cavity, round and smooth in the interior, where 

 she deposits from two to four hundred eggs. This nest, 

 with the passage to it, resembles a bottle with the neck bent. 



SUBGENUS GRYLLUS PROPER. 



No broad anterior feet. The Field-Gryllus digs for him- 

 self a very deep hole in a dry soil, exposed to the sun, and 

 here lies in wait for Insects. 



GENUS II. LOCUSTA, Geoff. 



Same musical instruments as the Gryllus ; mandibles less 

 indented, and galea broader ; elytra and wings tectiform ; 

 tarsus composed of four joints ; always a projecting ovipositor 

 in the form of a sabre, in the females. 



GENUS III. ACRYDIUM. Cricket. 



Stridulation of the males produced by rubbing the thighs 

 against the elytra or wings ; no projecting ovipositor in the 

 females ; elytra and wings tectiform or inclined ; tarsus com- 

 posed of three joints ; antennae sometimes filiform and cylin- 

 drical, sometimes in the form of a sword, or terminating in a 

 club, and always as long as the head and corselet. Certain 



