’ A. M. Mayer—Researches in Acoustics. 93 
placed it beyond all doubt by careful researches made on 
anterior side of the trachean vesicle. Upon this band is situ- 
ated a row of transparent vesicles containing the same kind 0 
cuneiform, staff-like bodies, mentioned as occurring with the 
crididz, The two large trachean trunks of the fore-legs open 
by two wide, infundibuliform orifices on the posterior er 
of the prothorax, so that here, as with the Acrididz, a part of 
this trachean apparatus may be compared to a ustachit, 
With the Achetide, there is, on the external side of the tibia 
of the fore-legs, an orifice closed by a white, silvery membrane 
(tympanum), behind which is an auditory organ like that just 
described. (With Acheta achatina and tala, there is a tympa- 
num of the same size, on the internal surface of the legs in 
question ; but it is scarcely observable with Acheta sylvestris, : 
A. domestica and A. campestris.)” : 
Other naturalists have placed the auditory apparatus of 
diurnal lepidoptera in their club-shaped antenne ; of bees at 
the root of their maxille; of Melolontha in their antennal 
plates; of Locusta viridissima in the membranes which unite 
the antenna with the head. 
