122 CRABS AND INSECTS. 
Fic. 149.—Seventeen-year cicada. 
ah 
Fic. 150.—A portion of a grass- 
stem, with the young froth-in- 
sects (Prye/us) magnified. a, 
the insect reaching out the 
hinder part of the body to se- 
cure a bubble of air; 4, an in- 
sect allowing a bubble of air 
to escape in the fluid—the dot- 
ted line 4 indicates the bub- 
ble; c, the mouth-parts, like a 
sting, piercing the grass. (Af- 
ter Morse.) 
bering 400 or 500, are depos- 
ited the last of May in holes 
in the twigs of the oak, so 
formed by the ovipositor that 
the wood covers them. They 
hatch in about six weeks, the 
larve burrowing in the ground 
and remaining nearly seven- 
teen years, then appearing in 
the adult form. Allied to them 
are the lantern-flies (Pulgo- 
rida).* 
Leaf-Hoppers (Cercofz- 
de).—The tree- or leaf-hop- 
pers are remarkable for their 
strange shapes. They are 
small, with broad, triangular 
heads, and hind-legs. adapted 
for leaping. The froth-insect 
* The following authors have ex- 
pressed their belief from observation 
and other sources in the phosphores- 
cent properties of the Fulgoride : 
Madame Merian, Dr. Donovan, au- 
thor of ‘‘ Insects of India,” Marquis 
Spinola, a colleague of Mr. West- 
mael, Lady Seymour, and Dr, Phip- 
son. 
