NATURAL HISTORlT OF AFRICA. 463 
14. Aptenodytes, penguin. One species, which 
is peculiar to Africa. 
III. — -Amphibious Animals. 
Reptiles. 
Of the tortoise tribe, the most frequent species 
in that named Tyrse (Trionyx iEgyptiacus, Geoff.) 
which is about three feet long, green spotted with 
white, and is singularly useful in Egypt by devour- 
ing the young crocodiles the moment they are 
hatched. 
The common crocodile, or the crocodile of the 
Nile has been long celebrated. It was formerly 
abundant in Lower Egypt, but at present it is 
principally met with in Upper Egypt. It is very 
abundant in all the rivers of Guinea, and also in 
the Senegal. The monitor of the Nile or Oua- 
ran, the Lacerta Nilotica of Linnaeus, a species of 
lizard three feet long, was much venerated by 
the ancient Egyptians, because it devours the eggs 
of the crocodile. In Congo, there is another mo- 
nitor lizard, six feet long, and which is useful to 
the inhabitants by devouring vermin of different 
kinds *> and the terrestrial monitor of Egypt, the 
our an el hard, which is common in the deserts 
that bound Egypt, is the terrestrial crocodile of 
Herodotus, and the true scinque of the ancients. 
The common chameleon, so famous on account of 
the power it possesses of changing its colour, is a 
