EXERCISE X. 
THE STICK INSECT (Bacillus). 
Sub-kingdom—ARTHROPODA.  Class—INSECTA. Order—ORTHOPTERA. 
Hamily—PHASMID, 
1. External characters.—Kill the animal by putting it 
into the killing bottle. It is divided distinctly 
into head, thorax and abdomen. The head is oval, 
sub-depressed, with large globular compound eyes, in 
front of which are the antennze, many jointed, the 
two basal joints being larger and flatter. There are 
no ocelli. The thorax is divided into three parts, 
prothorax, mesothorax, and metathorax, each of 
which carries a pair of legs. There are no wings. 
The prothorax is small; the mesothorax and meta- 
thorax are long, with a pair of legs at the posterior 
end of each. The basal joints of the lees—the coxze 
—are short and thick ; then follows the proper third 
joint (femur), the trochanter being absent, and the 
fourth (tibia) are long, and about equal in length. 
The tarsi are five-jointed, and have two claws, with 
a cushion, or pulvillus, between them. This is some- 
times called a sixth joint. Each segment of the 
thorax is formed by two plates—a dorsal, called the 
notum, and a ventral, called the sternum. In the 
connecting membrane between the prothorax and the 
mesothorax, and between this and the metathorax, 
just where the nota and sterna meet, is a spiracle— 
