STRIDULATION OF INSECTS. 97 



with its aid satisfy myself that the bow was striated. We 

 should expect the song of the wood-cricket to be feeble and 

 monotonous, on account of the elytra consisting of a softish 

 and scarcely sonorous membrane, and the simple form of the 

 musical instrument, and also from the absence of the brush : 

 and in fact the sounds produced by this insect are less song- 

 like than those of the field-cricket. 



The female has no instrument on her elytra, and is conse- 

 quently mute. Both sexes are furnished with the velvety 

 appendages at the extremity of the abdomen, and mirrors on 

 their fore-legs. 



Another speifies, the mole-cricket ( Gryllotalpa vulgaris), is 

 very common in the province of Gex, and does considerable 

 injury in the gardens. I have never heard them sing when at 

 liberty or in a state of captivity, but I have produced the 

 stridulatory sound both on a living and dead insect, by slightly 

 raising the elytra and rubbing them against each other. 



The elytra of the mole-cricket are perfectly symmetrical. 

 There is on the back-cover a musical instrument analogous to 

 that possessed by the before-mentioned insects : they have the 

 striated bow, the treble-string, and a single large nervure 

 which descends from the inferior origin of the bow in an 

 oblique direction towards the extremity of the elytron : I have 

 not observed the brush. This instrument being more simple 

 than that of the field-cricket, is not capable of producing such 

 varied sounds. Latreille says he heard the song of this insect 

 only in the evening or during the night, and that it is soft and 

 pleasing. It is only the male that sings. The elytra of the 

 female are simple like those of the female field-cricket, and 

 consequently incapable of producing sounds. The mole- 

 cricket possesses the velvety appendages at the extremity of 

 the abdomen, but I have not observed any thing resembling 

 the mirrors on the legs of the other crickets, though from 

 analogy I was led to look for them. 



In order to speak of all the crickets I have found in the 

 country in which I reside, I should mention Xya variegata, 

 Illig., a very small species which lives in the fine sand of the 

 islands in the Rhone below Cologne. It is met with in the 

 spring. It is generally found on the sand ; but is often seen 

 emerging from the sand, in which it buries itself and hollows 

 out galleries either for the purpose of concealment, or to seek 



NO. II. VOL. v. o 



