TORTOISES AND TURTLES. 109 



turtle is of strictly herbivorous habits, the fierce 

 Hawksbill is as purely carnivorous. Another very 

 remarkable group of marine Chelonians is now repre- 

 sented only by the so-called Leathery-turtle, which 

 differs from all other living forms in that the shell is 

 represented only by a carapace composed of a number 

 of small bones closely joined together, and forming a 

 mosaic-like structure which is totally unconnected with 

 the ribs. The living leathery-turtle attains a length 

 of about five feet; but some allied fossil forms are 

 estimated to have been as much as ten feet in length, 

 and were thus veritable aquatic giants. The largest 

 existing representatives of the true tortoises are, or 

 were recently, found in certain islands of the Indian 

 Ocean, and also in the well-known Galapagos (or 

 Tortoise) Islands lying off the coast of South America. 

 A magnificent series of these giant land- tortoises is 

 now exhibited in the Natural History Museum at 

 South Kensington. Many of these huge creatures, 

 which have in some cases been completely extermi- 

 nated by sailors, could readily walk off with a man 

 seated on their back ; and in the larger forms the 

 length of the shell in a straight line is upwards of four 

 feet. These dimensions were, however, vastly exceeded 

 by certain fossil species found both in Northern India, 

 the south of France, and elsewhere ; the shells of some 

 of these monsters attaining a length of six feet. The 

 late Dr. Falconer, who was disposed to consider that 

 the size was considerably greater than this, has indeed 

 suggested that some of these huge tortoises may have 



