138 TRUE TALES OF THE INSECTS. 



protecting the sides of the body. Both sexes are 

 possessed of sound-producing organs, though the female 

 is deficiently provided as compared with the male. On 

 examining the first abdominal segment in either sex, a 

 peculiar swelling is seen bearing two or three strongly- 

 raised chitinous folds, which being struck by some 

 peg-like projections on the inner side of the base of 

 the femur, a considerable noise is produced. Immediately 

 behind the folds, there is a prominent striated surface ; 

 this is rubbed by some fine asperities on the inner part 

 of the femur. These structures appear to be phonetic, 

 at least in the male ; in the female they appear to be 

 somewhat less well developed than in the other sex. 

 The male has still another phonetic structure. His 

 tegmina, though rudimentary, are much longer than in 

 the female, and their prolonged part is strongly ridged, 

 over which moves the edge of the denticulate and 

 serrate femur, giving rise to a louder and different 

 sound. In the female there is nothing analogous to 

 this ; and there can be little doubt it is a sound- 

 producing instrument peculiar to the male. In situation 

 it approaches the musical apparatus of the males of the 

 Stenobothri and other Acridiidae. Methone anderssoni 

 possesses large tympanal organs, which the small 

 tegmina cover up. 



In no other member of the Eremobiens, in no other 

 Orthopteron, are the phonetic organs so complex as 



