^ 327. THE INSECTA. 407 



are caused by the rubbing of their prothorax against the peduncle of the 

 mesothorax, or by grating the ridges of the abdomen against the internal 

 surface of the elytra. Reduvius stridulus, Mutilla europaea, and Mantis 

 religiosa, produce also certain sounds by the friction of particular portions 

 of their skeleton.'^' The males of many Acrididae produce their creaking 

 sounds by playing, as with the bow of a violin, upon the lateral borders of 

 their Elytra, by their posterior thighs which have a longitudinal granular 

 ridge on their internal surface.'^' The peculiar cry of the male Locustidae 

 and Achetidae is produced by the base of their elytra. The very hard 

 and sharp internal border of one of these elytra rubs against a horny ridge 

 upon the under surface of the other, close to the tympanitic disc.*^- 



With the males of the musical Cicadidae, there is a very remarkable sonif- 

 erous apparatus, situated on the under surface of the first abdominal 

 segment. It consists of two spacious drums at the base of which is a dry, 

 plicated membrane, to which is attached a large muscle of conical form, 

 arising from a median, bifurcated process of the second abdominal segment. 

 The entrance of each of these drums is more or less covered by a round- 

 ing operculum which is free behind. The muscle draws the membrane 

 inwards, then relaxing, this last returns by its own elasticity, producing, as 

 from the bending up and down of a metallic plate, a loud, clanging sound. 

 This sound is undoubtedly considerably increased by the resonance of the 

 air in the drums and in the neighboring vesicular tracheae.'"' 



to be explained in various ways, but none of the 6 For this soniferous apparatus, see Goureau 



causes yet assigned are satisfactorv ; see Passerini, and Solier, Ann. d. la Soc. Entom. 1837, p. 31 ; 



Ann. d. Sc. Nat. XIII. 1S28, p. 332 ; R. Wasner, Newport, Cyclopaed. loc. cit. II. p. 928, fig. 394- 



iii Sliiller's Arch. 1836, p. 60 ; Goureau, Nord- 396 ; Goldfuss, Symb. ad. Orthopt. quorund. 



maiin, and Duponckel, Ann. de la Soc. entom. A'l. oeconomiam, Bonn. Diss. 1843, p. 5, fig. 1-10 -, and 



-IX., or ffiegmann's Archiv. 1839—11.* my observations in Wie^mannKs Arch. loo. cit. p. 



i See Burmeister, Ilandb. &c. I. p. 507, and 69. Burmeister (Handb. &c. I. p. 511) has 



Goureau, in Silbe^man's Revue Entom. HI. p. sought to explain this sound by referring it to the 



101. powerful escape of the air from the stigmata of the 



5 See my observations in Wiegmann''s Arch. Locustidae and Acrididae ; but this is unsatisfac- 



1844, I. p. 53. This fiddling movement may be tory. 



easily observed with the males of Gomphoceros "i For the soniferous apparatus of the musical 



and Oedipoda. Pveumora maculata has, upon Cicadidae, see Riaumur, Mem. V. 4th mem. PI. 



the sides of the second abdominal segment, a very XVII. ; Burmeister, Handb. &c. I. p. 513 ; 



strongly denticulate, oblique ridge, against which Ratzeburg, Mediz. Zool. II. p. 208, Taf. XXVII. 



is rubbed, probably, a horny process situated on and especially Cams, Analekt. zur Naturwiss. p. 



the internal surface of the posterior thighs. I am 142, fig. l-18.t 

 yet unable to account for the waj- in which the 

 males of Oedipoda stridula produce their hoarse 

 buzzing, during flight. 



* [§327, note 3.] Haldeman {Sitlimari's 3o\xx. European Acherontia atropos may produce its 



May, 1848) states that Lithosia miniata, Kuby, peculiar sound in a similar manner. — Ed. 



or an allied species, produces an audible stridula- t [ § 327, note 7.] See also my investigations 



tion by vibrating the pleura beneath the wings, upon this apparatus of the Cjcada «ep<endec27?i in 



this part being marked in recent specimens by par- the Proceed. Boston Soc. Nat. Hist. 1851, p. 72. — 



allel lines, apparently indicating the position of the Ed. 

 muscles. According to him, it is possible that the 



