230 
The Queensland Naturalist. 
VoL. I. 
anybody in society, never startled by a bang, never tortured 
by a railroad whistle, never hearing the nasty cicadas in 
Italy, nor a child cry, nor an owl.’’ 
The specimens of Tho'pha saccata exhibited this evening 
render a technical description of the species unnecessary, 
but I have pleasure in referring members to an article by 
Mr. W. W. Froggatt, entitled — “ Cicadas (‘ Locusts ’) and 
their Habits ” ; (Ag. Gaz., N.S.W., 1903, p. 334) Avhich 
throws considerable light upon the life-hisiory of some of 
our large typical forms ; and to a valuable monograph of 
the Australian Cicididae (Pro. Linn. Sec., N.S.W,, 1904) in 
which he and Dr. Coding have described 120 species. 
Attempts to describe strident screaching notes such 
as those chaiacteristic of many of these insects, are generally 
more or less unsatisfactory, and it seems to me that when 
possible a verbal description could with advantage be 
supplemented by a record of the position such sounds would 
occupy in a stave of music ; as by this means their altitude, 
and the intervals between them could be correctly registered. 
Before mentioning the result of what may be termed an 
analytical investigation of the song of saccata, it will be 
advisable to consider for a moment the nature of the 
mechanism by which it is produced. Mr. Froggatt, in his 
article already alluded to, tells us that — “ The male has a 
large plate on either side of the under surface of the body 
attached to the corselet, but extending over the basal por- 
tion of the abdomen, beneath which is a cavity formed 
into tv'O (jells, occupied by two small, thin, glass-like plates, 
which Reaumur called mirrors ; above these are btindles 
of muscles, which lead to two membranes formed like kettle- 
drums, each of which has a convex and concave part, the 
first of which is folded and full of ridges.” HasAA^ell describes 
tlie action thus — “ The loud shrill note emitted by the 
insect is the result of a quick succession of crackling sounds 
produced by the movement of the stiff membrane Avith its 
horny ribs, through the agency of the muscle. Undei- 
ordinary circumstances, the sounds folloAv one another 
Avith sufficient quickness to produce a continuous note, 
and this is effected not by the contraction of the muscle 
as a Avhole, but by the successive contraction of individual 
fasciculi (different filaments forming the Avhole), all of 
which act on the horny plate, and thus the movements of the 
muscle on the tendon during the production of the note 
resemble those of the hammer-board of a piano AAffien a 
number of keys are being struck in quick succession.” 
Song of Thoplia saccata. 
The usual song of this species on a hot da}^ when heard 
at its maximum altitude, viz. : full cry, is pitched either 
Hortus Inclusus’ miscellaneous letters, p. 132. 
