2414 TORTOISES, TURTLES, AND PLESIOSAURS 



would accord well with the account given by L,eguat, 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. ' ' 



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



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

 Tortoises . ^ r 



one or more species of giant tortoise. Of the various species inhabit- 

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

 illustration on p. 2410, agrees with two others (T. nigra and T. vitina) 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 shells is of 

 considerable length, and the shell itself stout. On the other hand, in the saddled 

 tortoise (T. ephippium) and the Abingdon tortoise (71 abingdoni) the same bridge 

 is relatively short, and the shell is remarkable for its thinness; the carapace being 

 much narrowed anteriorly, where it is so pinched in at the sides as to have a sharp 

 ridge on the back. In the former of these two species the shell still retains the 

 usual bony framework, but in the second it is soft and leathery. Both have very 

 long necks, which are carried nearly vertically; and in the Abingdon species the 

 notches in the front end of the shell are so large that in a front view the animal ap- 

 pears merely to have a kind of mantle thrown over the body. It is hard to see 

 what can be the object of this softening and atrophy of the shell, but it is quite 

 clear that it renders the animals very liable to injury, and thus probably accounts 

 for the fact that none of them have been brought alive to Europe. The carapace of 

 this species attains a length of thirty -eight and one-half inches, and the weight of 

 one individual was just over two hundred pounds. 



The best account of the habits of the Galapagos tortoises is one given by Dar- 

 win, regarding the species figured in our engraving, which inhabits, apparently, 

 most of the islands of the group. These tortoises frequent in preference the high 

 damp parts, although they likewise live in the lower and arid districts. They are 

 very numerous, and some grow to such a size that it requires six or eight men to- 

 lift them, while they will yield as much as two hundred pounds of meat. "The old 

 males are the largest, the females rarely growing to so large a size; the male can be 

 readily distinguished from the female by the greater length of the tail. The tor- 

 toises which live on those islands where there is no water, or in the lower and arid 

 parts of the others, feed chiefly on the succulent cactus. Those which frequent the 

 higher and damp regions eat the leaves of various trees, a kind of berry, which is 

 acid and austere, and likewise a pale green filamentous lichen, that hangs in tresses 

 from the boughs of the trees. The tortoise is very fond of water, drinking large 

 quantities, and wallowing in the mud. The larger islands alone possess springs, 

 and these are always situated towards the central parts, and at a considerable 

 height. The tortoises, therefore, which frequent the lower districts, when thirsty. 



