THE MARSH-TORTOISES. 325 



The marsli-tortoises may be said to form the connecting link 

 between the eminently aquatic marine and river chelonians and 

 the land-tortoises, as the formation of their feet, armed with 

 sliarp claws or crooked nails, and furnished with a kind of 

 flexible web, connecting their distinct and movable toes, allows 

 them both to advance much quicker on the dry land than the 

 latter, and to swim rapidly either on the surface or in the depth 

 of the waters. 



Endowed with more rapid powers of locomotion, they are 

 not vegetarians, like the land-tortoises, but chiefly live on 

 mollusks, fishes, frogs, toads, and annelides. 



The river-tortoises differ in many respects from the sea- 

 turtles, although formed like them for a purely aquatic life. 

 In both families the extremities are complete fins, serving as 

 oars, but the fore feet of the river-tortoises are not double the 

 length of the hind feet, as we find in the marine chelonians ; 

 and while the latter have a short apoplectic neck, that of the 

 river-tortoise is generally very long, and surmounted by a small 

 and narrow head. The river-tortoises are exclusively confined 

 to the warmer countries of the globe, and sometimes weigh as 

 much as seventy pounds. It seems that during the night, and 

 when they fancy themselves secure from danger, they repose 

 upon the small river islands, or on rocks and trunks of trees 

 that have fallen on the banks, or are drifted along by the 

 current, and instantly plunge again into the water at the sight 

 of man or at the least alarming noise. They are extremely 

 voracious, and being very active swimmers, kill numbers of 

 fish and reptiles. When they wish to seize their food or to 

 defend themselves, they dart forwards their head and long neck 

 with the velocity of lightning, and are said in this manner to 

 surprise and seize even small birds that incautiously fly too 

 near the surface of the water. They bite lustily with their 

 sharp beak, never quitting their hold till they have fairly 

 scooped out the morsel, so that the fishermen stand in great 

 awe of their powerful mandibles, and generally cut off their 

 head as soon as they are caught, rightly judging this to be the 

 most radical means to prevent any further mischief. The 

 Indians of the Amazons catch them either with the hook, net, 

 or arrow. The last is the most ingenious method, and requires 

 the most skill. The tortoise never shows its back above water, 



