REPTILES OPHIDIANS DIAGRAM 5. 89 



black tongue now and then, which is bifurcated at the end, like 

 that of all lizards and serpents, but which cannot do any injury 



CROCODILES. Crocodiles and Alligators are a kind of large 

 lizards which inhabit the rivers of 

 hot countries. They sometimes 

 grow to a considerable size, and 

 attain a length of five or six yards. 

 They have a great number of 

 pointed teeth, and are very voracious. Hend of Crocodile. 



They live chiefly on fish, but often seize and devour quadrupeds 

 in the water, and even men when bathing. They come to bask in 

 the sun on the bank, and only move on land with difficulty ; 

 but they recover all their agility on the water, where they can 

 dive for a very considerable time. 



OPHIDIANS. 



[ DIAGRAM 5. ] 



Ophidian is derived from the Greek word ophis, which means 

 serpent. There are in this country only two races of serpent?, 

 one of which, the Viper, is venomous, and the other, the Common 

 Snake, is not. The viper is the smaller; it may be known at 

 once by its brown colour, with a broad undulating black line along 

 the back ; and it has a much broader head, and shorter tail, than 

 the common snake. On the top of the head, this black line is 

 double, and forms a V. 



The viper only is venomous. On opening the mouth of a dead 

 viper, which must always be done with great caution, because there 

 is still some danger, we find, in addition to a number of fine sharp 

 teeth, two teeth much larger than the others. They are situated 

 on each side of the upper jaw, close against it, and partly covered 

 by a fold of skin. These teeth are called fangs, and are not firmly 

 fixed in the jaw like the others ; they lie against the gum, or are 

 raised at the wish of the animal, by a joint at the base. On 



