332 MOSTLY MAMMALS 



as remains of other, although smaller, forms have been 

 discovered in the same deposits. The nearest living ally 

 of the Siwalik species appears to be Testudo emys, of the 

 countries east of the Bay of Bengal, in which the shell 

 does not much exceed a foot in length. Both kinds have 

 the front end of the lower shell produced and notched, 

 although the production and notching are much more 

 pronounced in the extinct form. Both also have the horny 

 shield immediately' above the tail double, instead of (as is 

 usually the case) single ; and in both the skin of the legs 

 contained embedded nodules of bone. 



The Pliocene deposits of the South of France have also 

 yielded remains of a giant land-tortoise {T. perpiniand), 

 with a shell about four feet in length, and likewise furnished 

 with bony nodules in the skin of the limbs. And from 

 the caves of Malta have been obtained bones of yet 

 another very large species (T. robusta), apparently allied 

 to the recently extinct T. tnepta of Mauritius. 



Going farther afield, we find evidence of the existence, 

 during late Tertiary times, of giant land-tortoises in North 

 America, while some imperfect shells attest the former 

 occurrence of another species in Patagonia. It may be, 

 therefore, assumed that during the Pliocene, and perhaps 

 a portion of the Miocene epoch, land-tortoises of huge 

 size were spread over the greater portion of the warmer 

 countries of the globe. 



With, or before, the close of the Pliocene division of 

 geological time, these great reptiles seem, however, to have 

 utterly vanished from all the continents of the world, and 

 to have continued to exist only in certain islands, from 

 some of which they likewise disappeared before or during 

 the early portion of the historic period, while others have 

 become extinct quite recently. Whether these island giant 



