222 BACKBONED ANIMALS. 
NoTe.—The most remarkable land tortoise is the 7estudo nigra, or 
elephant turtle, of the Galapagos Islands. They attain a length of six 
feet, and eight men can barely lift the largest. They feed upon the 
cactus, and their paths from the springs can be seen all over the islands. 
Though large and clumsy, they can travel eight miles in three days, 
The eggs are spherical, and larger than a hen’s egg. They are either 
buried in the sand or dropped among the rocks. During the breeding- 
season the male utters a hoarse roar or bellow. They are valued for 
their flesh and oil. The Colossochelys is an extinct land tortoise of the 
Tertiary period, found in India. They were twenty feet in length, 
the shell being twelve feet long and six feet high, and would serve as a 
covering for six or seven men, 
Order IV (Rhynchocephalia).—This order is represented 
bya single animal—the Sphenodon punctatus, or Hatteria, of 
New Zealand. Its general appearance is like the iguana, 
having a similar row of dorsal spines. It attains a length 
of three feet, and forms a burrow, lining it with grass, 
that is also occupied by three species of birds—petrels, 
etc. The lizard occupies one side of the nest and the 
birds the other. It is nocturnal in its habits, and lives to 
some extent upon the food the birds bring in to their 
young. : 
Order V. Crocodiles (Crocodilia). General Charac- 
teristics—The crocodiles and alligators form the highest 
order of existing reptiles. The brain and heart closely 
resemble those of the birds. Their skin is covered with 
bony plates, and the teeth are lodged in separate sockets ; 
the nostrils can be closed, and the feet are partly webbed. 
They lay twenty or thirty eggs, that are buried in the sand 
and hatched by the sun. 
Alligators (Ad/catoride),—The alligators,* of which 
ten species are known, are distinguished by having both 
* Their nests are sometimes in the sand or in mounds of decayed 
vegetation. In the colder months they hibernate in the mud. In 
Nicaragua they have been known to seize human beings, pigs, and 
even horses, often drifting down upon their prey, their bodies resem- 
bling submerged logs. Their voice is a loud bellow like that of a bull. 
