184 THE AMERICAN MIDLAND NATURALIST 
CARAPACE PLASTRON 
Length Width Length r 
SD = CM. Daler 25. SCM: 
Sane CM: B.20 Chk 2205 em! 
3.43 cm. 3.20 cm. 2.60 cm. 
3.67 cm. 3:20 CM. SM GANG 48 
Bc CM. o.2 ecm. 24AT emis 
Weight of an average specimen: 4.97 ers. 
The eggs in the artificial nests hatched on July 29, 30, 31. 
Observation on the island showed that the nests hatched there 
from July 31 up thru the early part of August. In escaping 
from the nest the young turtle leaves the egg shell below the 
surface and tunnels almost vertically upward, leaving a hole 
in the sand about an inch in diameter to mark the spot of 
escape. On spots where nests have hatched a number of 
these holes may be seen on the surface within several inches 
of each other. No newly hatched turtles were found on the 
island. They always hatched during the night or early morn- 
ing, and probably lost no time in getting to the water. Un- 
der favorable conditions the period of incubation is from 
seventy to seventy-fiv@ days, depending upon circumstances - 
of heat and moisture. 
The young exhibit a marked geotropism, always going 
downhill, and are photokinetic upon any disturbance. Since 
the nests are usually so situated that an open sky and sloping 
beach are presented in the direction of the water it is prob- 
able that these two factors guide the young to the river. They 
are perfect swimmers immediately after hatching and if held 
and irritated they make repeated efforts to bite. Placed in a 
sand bottomed acquarium they dig under at once, coming out: 
again only after the suspected danger has passed. They seize 
edible morsels eagerly after a thorough probing with their 
flexible noses. At least six or seven years are required before 
they attain edible size. 
