NdTSES OF INSECTS. 399 



hopper lark (Alauda trivmlis, L.)j vvliich preys upon 

 them, makes a similar noise. Professor Liclitensiein 

 in the JJiuiean Transactions has called the attention 

 of naturalists to the eye-like area in the right wing of 

 the males of this genus* ; but he seems not to have been 

 aware that De Geer had noticed it before him as a 

 sexual character ; who also, with good reason, sup- 

 poses it to assist these animals in the sounds they pro- 

 duce. Speaking of Locusta ziridissima — common with 

 us — he says " In our male grasshoppers, in that part 

 of the right elytrum which is folded horizontally over 

 the trunk, there is a round plate made of very fine 

 transparent membrane, resembling a little mirror or 

 piece of talc, of the tension of a drum. This mem- 

 brane is surrounded by a strong and prominent ner- 

 vure, and is concealed under the fold of the left ely- 

 trum, which has also several prominent nervures an- 

 swering to the margin of the membrane or ocellus. 

 There is/' he further remarks, " every reason to be- 

 lieve that the brisk movement with which the grass- 

 hopper rubs these nervures against each other, pro- 

 duces a vibration in the membrane augmenting the 

 sound. The males in question sing continually in the 

 hedges and trees during the months of July and Au- 

 gust, especially towards sun-set and part of the night. 

 When any one approaches they immediately cease 

 their song''." 



The last description of singers that I shall notice 

 amongst the Gryllidae, are those that are more com- 

 Mionly denominated grasshoppers (Grt/lhis, F.). To 

 this genus belong the little chirpers that we hear in 



* Linn. Trans, iv. 51 — •" De Gecr,.iii. Hi), 



