TOWER-BUILDING CICADA. 
LOSELY allied to the bugs is a group of remarkable 
insects to which naturalists now apply the name 
of Cicada, but which are generally, though improperly, 
designated Locust by the common people. They are readily 
distinguished by their broad heads, large prominent eyes, 
with three eyelets triangularly placed between them, and 
delicately transparent, veined wing-covers and wings. The 
abdomen is short and pointed, and the legs are short, the 
anterior femora being much thickened and toothed beneath. 
The hinder extremity of the body of the female is conical, 
and the under-side has a longitudinal channel for the recep- 
tion of the ovipositor, or piercer, which is furthermore pro- 
tected by four short-grooved pieces which are immovably 
fixed to the sides of the channel. The piercer itself consists 
of two outer parts grooved on the inside and slightly 
enlarged and angular at the tips, which are externally beset 
with small saw-like teeth, and a central spear-pointed borer 
which plays between the other two, thus combining the 
advantages of an awl and a double-edged saw, or rather of 
two key-hole saws cutting opposite to each other. A hard, 
horny substance, called chitine, the same as exists in the 
stings of bees and wasps, is the material of its composition. 
It would be impossible to conceive of anything more exactly 
fitted for its required uses than is this beautiful complicated 
instrument. 
But the most peculiar characteristic of this family, how- 
ever, consists in the structure of the mechanism by which 
the males make the trilling sound for which they have been 
