56 
TORTOISES AND TURTLES. 
thence to the Mauritius is the only living example of the species that formerly 
inhabited Rodriguez. Regarding the abundance of these tortoises in the latter 
island, Franyois Leguat, writing in 1691, observes that “ there are such plenty of 
land-turtles in this isle, that sometimes you see a three thousand of them in a 
flock, so that you may go above a hundred paces on their backs.” In Mauritius 
they were still abundant in 1740; but about 1761 they were probably scarcer, as 
thousands were then imported from Rodriguez as food for the patients in the 
hospitals of the Mauritius. The continued exportation,—some ships taking as 
many as four hundred at a time,—coupled with the destruction of their eggs and 
young, finally led to their extermination in both Mauritius and Rodriguez; this 
extirpation having probably taken place early in the present century. The 
Reunion tortoise, of which very little is known, seems to have disappeared at a 
still earlier date; while of the Galapagos species, we shall speak later. 
The total number of species of giant tortoises known to have existed within 
ELEPHANT-TORTOISE. 
the historic period is about fourteen ; the whole of which are characterised by their 
large size, their long necks, and the uniformly dark brown or black colour of their 
shells. They may be divided into four groups, according to their geographical 
distribution, each characterised by certain structural peculiarities. The first group 
comprises the four Aldabra tortoises, characterised by the presence of a nuchal 
shield on the front of the carapace, and the distinctness of the gulars on the front 
of the plastron. On the other hand, in the four best known Mascarene species, 
constituting the second group, the nuchal shield is wanting, while the two gulars 
have coalesced into one; the plastron being characterised by its extreme shortness. 
Lastly, the third, or Galapagos group, with six species, presents a condition inter¬ 
mediate between that existing in the two others, the nuchal shield of the 
carapace being absent, while the gulars of the plastron remain double. We 
proceed to notice some of the species of each group. 
Aldabra Tortoise best known of the four species from Aldabra is the elephant- 
tortoise ( T. elepliantina), which differs from the other three in having 
