5 6 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, FranQois 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. 



. The best known of the four species from Aldabra is the elephant- 



' tortoise (T. elephantina), which differs from the other three in having 



