154 THE LIVING ANIMALS OF THE WORLD 



these limbs take the form of flattened paddles, and in no 

 instance are more than two of the toes provided with claws. 

 The T()RT(.)ISES are sub-di\itled by zoologists into 

 some six or eight subordinate groups or families, for 

 the most part distinguished by the respective modifi- 

 cations of their [jrotective shells. This shell in all 

 tortoises and turtles consists of two essential elements — 

 the upper or back casing, known as the " carapace," 

 and the under one, or so-called " plastron," which 

 covers the ventral surface. In some forms these two 

 elements arc completely welded into one another, forming 

 a continuous box-like shell ; in others they are more or 

 less separate ; while in yet another series the lower 

 ■^hell is rudimcntar}-. These distinctions have been 

 found to constitute a convenient basis for classification. 



In the TKLfE Lanu-TORTOISES, which invite first 

 attention, the upper and lower shells are completely 

 united in a box-like form, and the neck, bent in the 

 form of the letter Si can be completely retracted within 

 it. The limbs are club-shaped, covered with horny 

 scales or tubercles, and adapted for walking, the toes 

 being unwebbed, and provided with strong claw-like nails. 

 Pre-eminent among this t}'pical terrestrial series 

 come the huge Gl.\NT or ELEPHANT-TORTOISES, formerly 

 abundant, as their fossil remains indicate, in Southern 

 Europe, India, and North and South America, and now 

 represented only in the isolated oceanic islands of Aldabra, 

 off Madagascar, the .Seychelles, and the Galapagos groups. 

 Even within historic times they were very abundant in 

 the islands of Mauritius and Rodrigucs; but their huge size and lethargic habits, combined 

 with their esculent qualities, have brought about their extermination. Those remaining in 

 the islands mentioned are now so reduced in numbers that there is a possibilit}- of their 

 becoming extinct at an early date, and this notwithstanding the strenuous endeavours that 

 are being made to save them. A large percentage of 

 the small residue of these giant Chelonians have been 

 transported from their island homes and presented to the 

 London Zoological Gardens, where they are now comfortably 

 housed. 



An instructive idea of the aspect and relative dimen- 

 sions of these giant tortoises may be obtained by a refer- 

 ence to page vii of the First Volume, in which one of 

 these Chelonians is shown to be equal in size and strength 

 to carrying a human rider. It is recorded that these 

 reptiles were so abundant in the island of Rodrigucs in 



1691 that one might count as many as 3,000 of them in "\'t:-"i.v?\. '"'ii'^-' ■" v ■' - 

 a single flock, and walk for over lOO paces upon their : ''',^^^^^;a?^"~^.^^'l*li;^*i.-'-'' 



/■(i.io if C. S. M. 



ASIATIC TORTOISES 



j4 tortcisfj !ike a turtle^ turned Ofer on iti hdck^ 

 rtprfitnti one of the most helpless oj lii'ing animals 



backs. All of these giant tortoises, as obtained from 

 separate island groups, or islets of the groups, exhibit 

 characteristic differences, indicating the length of time 

 they have been separated from one another. The 

 age to which these giant tortoises attain is altogether 

 phenomenal. One example at Port Louis, Mauritius, 



Photv b; C. N. Miivrtytni'] \_Sm>Tr.-i 



EUROPEAN TORTOISE 



A tortoise" s she/If or carapace^ constitutes a port' 

 able hotisey nvherein the animal can tntirely Kvith 

 li'-aiv for skelter in inclement iveatherj or ivhen 

 attacked hy enemies 



