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V. Observations on the C répit aciilum and the Foramina in the 

 anterior Tibicc of some Orthopterous Insects. By the Rev. Lans- 

 down Guilding, B.A. F.L.S, 



Read June 7, 1825. 



Of the organs possessed by the insect tribes, none merit dili- 

 gent examination more than those which are connected with the 

 production of sound. The structure of most of them is well 

 known at the present day, and has been elucidated by accurate 

 figures. Some, however, require further explanation. I shall 

 briefly notice one insect, and describe its crepitaculum, and the 

 tibial foramina of two orthopterous genera*. 



The subdiaphanous horny apparatus at the base of the wings 

 of the male Locustce and Achetée has long since been observed to 

 be the instrument inn stridoris by which the mute female is invited 

 by the male to celebrate their nuptials ; but the peculiar and 

 admirable structure of the part has not been shown in a satis- 

 factory manner by the engraver. In different species it varies 

 greatly, but in the one I shall notice it is exceedingly complete. 

 On the horny base of the left hemelytron, beneath, a strong ridge 

 projects, which is furnished with hard and regular teeth : on the 

 right one, a bony process is placed, so as to act on the serrated 



* Drawings of the several parts, by the author, are deposited in the collection of 

 the Society. 



VOL. XV. X projection 



