CHELODINA LONGICOLLIS. 
of food, which it readily takes from the hand. It occasionally comes on shore 
to snn itself, but speedily regains the water if disturbed, and always remains 
in it at night. One of its most remarkable habits is that it very frequently 
rises to the surface, and remains with only the anterior part of the head just 
behind the eyes emerged, the rest of the head with the whole body being 
under water, in which position it will continue motionless for a considerable 
time; a circumstance which shows a remarkable power of regulating its spe¬ 
cific gravity by the quantity of air taken into the lungs, as it must necessarily 
preserve the specific gravity of the water, excepting the small portion of the 
head which is exserted. When in this position, the remarkable brilliancy of 
the eyes, the smallness of its head, and the excessive length of the neck, render 
it a very peculiar and striking object. 
Like the whole family of Hydrcispidce , it retracts its head by bending the 
neck laterally, and from the great length of that part, it requires two com¬ 
plete duplications to conceal it wholly under the anterior edge of the upper 
shell, which, when thus retracted, it exactly meets, occupying the whole space 
between the fore legs. Its powers of swimming are considerable, as may be 
supposed from the narrowness of the alae of the sternum, allowing great space 
for the motion of all the legs. The feet present the remarkable anomaly of 
having four nails only on each. 
