596 
ARTICULATA. 
LANTEHN-FLIES. 
noise, which, as they are generally of large size, is often exceedingly loud and sometimes dis- 
agreeable. Nevetheless, the ancients, and 
particularly the Greeks, appear to have 
regarded this music, which is very un- 
pleasant to modern ears, with feelings 
of great satisfaction ; and the Cicada is 
often referred to with expressions of de- 
hght by the Greek poets. The apparatus 
by which the sound is produced consists 
of a sort of drum placed in a cavity on 
each side of the base of the abdomen ; 
this is pulled inward by the action of a 
particular muscle, and on being again let 
loose its vibration produces a loud, sharp 
tone. The drums are concealed by scale- 
like plates, which are sometimes so large 
as to reach nearly to the extremity of the 
abdomen. 
The female lays her eggs in slits, which 
she cuts in the bark of trees by means of 
a curious saw-like ovipositor; the branches 
are generally so weakened by the operation 
that they fall to the ground, when the larvas burrow down to the roots of the trees, upon which 
they feed, often occasionmg con- 
siderable damage. They appear 
to occupy at least two years in 
their development. In America 
the cicadas have the general name 
of Harvest-Flies ; they are also 
often improperly called Locusts. 
There are sev^eral species, one of 
which, the Red-eyed Cicada, C. 
septendecim, is remarkable on ac- 
count of the popular notion that 
it appears only once in seventeen 
years, in the same locality, being- 
supposed to pass the interval in 
its preparatory stages. Hence it 
is knovvu in this country as the 
Seventeen-year Locust. This idea 
is, however, unfounded; some of 
these insects appear among us every year, and they have manifested themselves in vast numbers 
at irregular intervals of five to ten years. This insect is very different from the locust of the Scrip- 
tures; indeed, there appear to have been eleven different species of insect spoken of in the Bible 
as locusts, but all of which were of the grasshopper family. 
THE CICADA. 
ORDER 11. THYSANURA. 
This order derives its name from the Greek thysanos, a fringe, and oura^ a tail, and includes 
two families, the one called Podaridcs, and the other Lepismidce. The former comprises the 
Springtails, having a forked tail, which is usually bent under the insect; by means of its sud- 
den expansion they effect a considerable leap. The latter have a long, spindle-shaped body, 
usually covered with silvery scales ; they are often seen in the sash-frames of windows. 
