6 4 



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 be 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- 

 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 spicler- 

 ' 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 



bell's hinged tortoise. 



Land-Terrapins. 



