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POPULAR SCIENCE REVIEW. 
of the folded membrane, and of the entogastrium , as well as 
the internal opening of the metathoracic stigma, are likewise 
to be seen in this figure. 
Fig. 2. The same apparatus seen from the side (left). The whole of the 
apophysis of the “ cavern ” has been removed in order to show 
the drum. A partial section has also been made of the oper- 
culum in order to show en profile the greater part of the details 
of the following figure. 
„ 3. The anterior part of the musical apparatus. A section of the 
operculum on its left side has been made to show the contained 
organs. In order that, the drum may be better seen, the bottom 
of the 11 cavern ” has been raised, its entrance remaining intact. 
„ 4. The lower part of the thorax and abdomen of the male of 
Cicada plebeia , seen from beneath. After fig. 2c, Planche 
XLV. of Cuvier’s u Regne Animal: lusecta.” 
a. Epimeron of mesothorax. 
/3. Epimeron of metathorax. 
y. First abdominal “ somite.” 
5. The musical organ of the same insect laid open and seen on its 
ventral aspect. Ibid. Fig. 2,/. 
a. Orifice of insertion of the hinder 
wing. 
la. First abdominal segment. 
2a. Second „ „ 
3a. Third „ „ 
ap, Apophysis of the folded mem- 
brane. 
c, “ Cavern.” 
c, u Cheville ” of Reaumur, or 
trochanter of leg of the third pair. 
e, The “ wing ” of the entogastrium 
in fig. 1, its “ body ” in fig. 2. m i, 
“ Mirror.” 
m m, Motor muscle of drum. 
mp, Folded membrane. 
m s, Sterno-entogastric muscle. 
m t, Tensor of the folded mem- 
brane. 
p, Leg of the third pair. 
s, Stigma of metathorax, 
s', First abdominal stigma, 
s , Second ,, ,, 
t, Drum (“ timbale ”). 
v, Operculum (“volet”). 
x, Semi-annular membrane of the 
muscle of the drum. 
