220 ANIMAL ACTIVITIES, 
How many bones compose the pelvic girdle ? 
By what kind of a joint is 
the femur attached to the 
pelvic girdle ? 
Drawing. Hind leg, 
naming bones. 
The Axial Skeleton. How 
many vertebre compose the 
back-bone ? 
How many ribs are present ? 
How many of these are fast- 
ened to the sternum ? 
How does a mammalian 
vertebra compare with a verte- 
bra of a fish ? 
How does the vertebral 
column in a mammal differ 
from that in the frog ? 
The vertebra on which the 
Fic. 178.—Skeleton of Go- Skull moves is called the atlas, 
rilla. the vertebra next back of that 
is called the axis. Can you 
find on the atlas smooth sockets corresponding to pro- 
jections on the skull ? 
The projections on the skull are called condyles. 
How many condyles are there on the mammalian 
skull? How many on the bird’s skull ? What purpose 
do condyles and sockets serve ? 
Do you find a quadrate bone on the mammalian 
skull ? 
What is the dental formula of the mammal you are 
studying ? 
What is the dental formula for the horse? For a 
squirrel? For a rabbit ? 
In the head of a horse, how does the area of face and 
cranium compare with the same areas in man ? 
(See figures.) Write resemblances and differences 
for skull of gorilla and man. 
