266 



INTRODUCTION TO ZOOLOGY 



The genus which comprises the greatest numher of species 

 is that of the Iguanas [Fig. 227), which are found only in 





-Iguaxa 



the New World. Some of these are so much as five feet in 

 length, and the colour a heautiful green of a variety of shades. 

 They have a singular crest along the back, and a hanging 

 pouch, like the dewlap of oxen, under the chin. This pouch 

 the}^ have the power of inflating with air. They live among 

 the branches of trees, and feed principally, but not exclu- 

 sively, upon leaves and fruits. Eggs and insects form a por- 

 tion of their diet.* 



Darker in colour and more repulsive in aspect are the 



i 



Fig. 228.— Gecko. 



Geckos {Fig. 228) or Nocturnal Lizards. "Though timid 

 and harmless, they are always regarded by the vulgar as 



• A gigantic fossil reptile discovered in the South of England, in 1834, 

 by Dr. Mantell, is named the Iguanodon, from its resemblance in many 

 points of structure to the Iguana. 



