LAND-TORTOISES. 



57 



the horny shields of the carapace concentrically striated, and the plastron of the 

 adult notched behind. One of the species (T. gigantea) with smooth shields on a 

 truncated plastron is peculiar in having the caudal shield divided, as in the 

 Burmese brown tortoise. The elephant-tortoise appears to be one of the largest of 

 all the species, attaining a length of about 4 feet. At the present day it is very 

 scarce in its native island, where the few survivors receive a certain amount of 

 protection from the Government of Mauritius, to which Aldabra belongs. There 

 are, however, a few individuals living in Mauritius and the Seychelles. 



Mascarene Of the Mascarene species, the three species from Mauritius 



Tortoises. (j 1 indica, trisserrata, and inepta), all of which are extinct, are 

 characterised by the thinness of their carapace, of which the margins are thickened. 

 The Rodriguez tortoise (T. vosmceri) has a still thinner carapace, which in the 

 male does not shelve down in front in the usual manner. Allusion has already 

 been made to the numbers in which these tortoises existed in Leguat's time ; but 

 till quite recently it was thought that the species was totally extinct. It appears, 

 however, that in the Artillery barracks of Port Louis in the Mauritius, there lives 

 a very ancient tortoise which, in the opinion of Dr. Gtinther, is probably of this 

 species. This tortoise is one of two which were imported into the Mauritius by 

 the navigator, Captain Marion du Fresne from the Seychelles in 1766; one of 

 these having been subsequently presented to the London Zoological Gardens in 

 1832 by Sir C. Colville. The latter weighed 289 lbs., and its shell measured 4 feet 

 4| inches in length along the curve, and 4 feet 9 inches in width ; while in the 

 Port Louis specimen the circumference of the shell is 9 feet 3 inches, and its height 

 2 1 feet. Marion's tortoise, as the Port Louis example is called, is thus definitely 

 known to have lived for a hundred and twenty-seven years, and as it was doubtless 

 of large size when brought from the Seychelles, and since all these tortoises take 

 an immense time to reach large dimensions, it is highly probable that it is an 

 actual survivor from the enormous herds that existed in Rodriguez in Leguat's 

 time. From a peculiarity in the structure of the hinder vertebras of the neck, it 

 appears that the tortoises of this species have the power of raising their necks to a 

 nearly vertical position, which would give them a wide range of vision. This 

 elevated range of vision would accord well with the account given by Leguat, who 

 writes concerning these tortoises as follows. " There's one thing very odd among 

 them ; they always place sentinels at some distance from their troop, at the four 

 corners of the camp, to which the sentinels turn their backs, and look with the 

 eyes, as if they were on the watch." 



Galapagos The various islands of the Galapagos Group, such as Abingdon, 



Tortoises. Albemarle, Chatham, Hood, and Charles, are the respective homes of 

 one or more species of giant tortoise. Of the various species inhabiting these 

 islands, the blackish tortoise (T. nigrita), which is the one given in the illustration 

 on p. 54, agrees with two others (T. nigra and T. vicina) in having the horny 

 shields of the carapace concentrically striated in the adult ; the figured species 

 differing from T. nigra in having the plastron notched, instead of truncate 

 behind. In the other three species the shields on the back are smooth, while 

 the plastron always has its hinder end truncated. In the North Albemarle 

 tortoise (T. microphyes), the width of the bridge connecting the upper and lower 



