440 MANUAL OF ZOOLOGY. 



world. The tongue is wide, flat, scarcely notched at its free 

 extremity, and hardly at all protrusible. The eyes are large, 

 with extremely short lids, the pupil liiostly linear, but some- 

 times circular. The teeth are numerous, small, compressed, 

 and implanted on the inner edge of the jaw. The nails are 

 mostly hooked and retractile, and the toes are furnished below 

 with imbricated plates. The animal is capable of running on 

 the smoothest surfaces, or suspending itself back-downwards. 

 They feed on insects, and are found in abundance in the warmer 

 parts of both the Old and New Worlds. 



The IguanidcB constitute another large family of Lizards, 

 also belonging partly to the Old and partly to the New World. 

 The tongue is thick, fleshy, notched at its extremity only, and 

 not protrusible. Mostly there is a dorsal crest, and a goitre or 

 throat-pouch. The body is covered with imbricated scales. 

 Only one species of the family is European, but the group is 

 represented by numerous species in N. and S. America, Asia, 

 Africa, and Australia. They are often divided into "ground- 

 iguanas," in which the body is flat and depressed, and " tree- 

 iguanas," in which the body is compressed. The members of 

 the genus Iguana itself (fig. 169) are confined to the New 

 World, and, are distinguished by haying the throat furnished 



Fig. 172.— Head of a Chameleon (C. Petsrsii)—a.il^-c Gray. 



with a pendulous dewlap or fold of skin, the edge of which is 

 toothed. The back and tail, too, are furnished with an erect 

 crest of pointed scales. The Iguana attains a length of from 

 four to five feet, and though not of a very inviting appearance, 

 is highly esteemed as food. The Basilisks {Basiliscus) have 

 the tog of the head furnished with a membranous sac, which 

 can be' distended with air at will. The Agamidm agree with 

 the Iguanas in most respects, but have two rows of teeth on 

 tlie hinder margin of the palate, and the tail is covered with 



