ARTHROPODA. 
303 
From twenty-two thousand to twenty-four thousand 
Lepidopterous species have been identified. Some of the 
most common Butterflies are the swallow-tail Papilio, 
the white Pieris , the sulphur- 
yellow Colias; the Argynnis , 
with silver spots on the under 
side of the hind wdngs; the 
Vanessa , with notched wings. 
The Sphinges exhibit little 
variety. They have narrow, 
powerful wings, and are some¬ 
times mistaken for Humming¬ 
birds. The “ potato-worm ” 
is the caterpillar of a Sphinx. 
The most conspicuous Moths 
are the large and beautiful 
Attacus , distinguished by a 
triangular, transparent spot 
in the centre -of the wing; 
the white Bombyx , or “ silk¬ 
worm the reddish-brown Clisiocampa , whose larva, u the 
American Tent-caterpillar,” spreads its web in many an 
apple and cherry tree; the pale, delicate Geometrids ; and 
the small but destructive Tineids , represented by the 
Cloth es-moth. 
7. Hymenoptera , comprising at least twenty-five thou¬ 
sand species, include the highest, most social, and, we may 
add (if we except the Silk-worm), the most useful, of In¬ 
sects. They have a large head, with compound eyes and 
three ocelli, mouth fitted both for biting and lapping, 
legs formed for locomotion as w T ell as support, and four 
wings equally transparent, and interlocking by small 
hooks during flight. The females are usually provided 
with a sting, or borer. The larvse are footless, helpless 
grubs, and generally nurtured in cells, or nests. Such are 
Fig. 276. — Head of a Caterpillar, from 
beneath: a, antennae; b, horny laws; 
c, thread of silk from the conical fusti- 
lus, on either side of which are rudi¬ 
mentary palpi. Magnified. 
