TORTOISES AND TURTLES. 
In habits the hinged tortoises show a complete transition from the land 
tortoises to the terrapins, and thus fully justifies the conclusion, arrived at from 
structural considerations, that both groups should he included in a single family. 
According to the observations of Monteiro, it appears that Bell’s hinged tortoise is 
essentially a land reptile, inhabiting regions formed of gneiss rocks or other dry 
localities, where it is active during the hot rainy season, but in the cooler portion 
of the year, from May to October, according to native reports, lies deeply buried in 
the earth. Both the other species, on the contrary, seem to be mainly aquatic in 
their habits; the dentated hinged tortoise, which is fairly common in Guinea, being 
stated to spend a large portion 
of its time in the water, where 
one specimen remained for up¬ 
wards of a month. According 
to Falkenstein, it is found in 
rivers, even close to the sea, 
from whence it emerges to lay 
its eggs on their banks. In 
spite of its club-like feet, it 
dives and swims with facility; 
captive examples descending to 
the bottom of a deep vessel in 
which they were kept. On 
land, its motions are, however, 
slow and deliberate in the 
extreme; and have been com- 
bell’s hinged tortoise. pared to those of the minute- 
hand of a clock. Its food is 
of a vegetable nature; one captive specimen displaying great partiality for cherries. 
By the inhabitants of Guinea these tortoises are eagerly sought after as food, and 
are thus difficult to obtain by Europeans. 
The last member of this section of the family is the spider- 
tortoise (Pyxis arachnoides ) of Madagascar, which is the sole 
representative of a genus characterised by the presence of a transverse hinge 
across the front of the plastron, by which means the anterior lobe of the latter can 
be bent upwards so as to close the front of the shell. In having the neural bones 
of the carapace alternately octagonal and tetragonal, this species approaches the 
true tortoises nearer than do the hinged tortoises. In length the shell is only just 
over 4 inches; its coloration is yellow, with radiating black bands from the centres 
of the shields of the back. 
The whole of the tortoises hitherto described are collectively 
characterised by the absence of all trace of webbing in the toes, by 
the presence of not more than two joints, or phalanges in each toe, by the meta¬ 
carpal bones of the fore-foot being but slightly, if at all, longer than wide, and 
also by the majority of the bony neural plates of the carapace being hexagonal, 
with their shorter lateral surfaces posteriorly placed, or alternately octagonal and 
tetragonal. On the other hand, in the remaining members of the family, the 
Spider-Tortoise. 
Land-Terrapins. 
