12 INVERTEBRATE ZOOLOGY 
margin of the mesosternum and of that of the first 
sternite with the metasternum, also the attachment of 
the legs. 
e 
Exercise 5. Remove a metathoracic leg and draw an outline of it 
on a scale of 8. The segment by which it articulates with 
the body is the coxa; the next segment is the trochanter, 
which in the grasshopper, however, is not a free segment, 
but is fused with the following one, the femur; the latter 
is the largest segment of the leg and has V-shaped muscle 
impressions on its surface; the next segment is the tibia 
or shank; the end segment is the tarsus or foot, which is 
made up of five smaller segments; the terminal one of 
these bears two claws between which is a structure called 
the pulvillus. This organ is an adhesive pad which enables 
the animal to walk and spring on smooth surfaces. Label 
all of these parts. 
Exercise 6. Draw an outline of the face on a scale of 5 or 6. 
The large plate which forms the top, front, and sides of 
the head, in which the eyes, ocelli, and antenne are situ- 
ated, is called the epicranium. The sides of the epicranium, 
back of the eyes, are the gene, the top is the vertex, and 
that part which forms the anterior surface is the front. 
Ventral to the epicranium is a broad, short, median plate 
called the clypeus, beneath which is the upper lip. The 
antenne are the first pair of appendages. Label all parts. 
The mouth-parts. These consist of the median upper lip or 
labrum, the paired mandibles, the paired maxille, the median hypo- 
pharynx, and the paired under lip or Jabium. The paired mouth- 
parts are the second, third, and fourth pairs of appendages, the 
antenna being the first pair. 
Exercise 7. Remove the labrum with scissors and draw it on a 
scale of 5. 
