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these outgrowths are of much use in breathing, but they can be 

 distended with air so as to swell out the body. This may be a 

 protective arrangement. 



Nearly fifty species of Chameleon are known, of which the 

 vast majority are natives of Africa and Madagascar, though 



Fig. 143. Common Chameleon (Chainezleo vulgaris) 



outlying members of the group are found in Arabia, India, 

 and Ceylon, while one species, the Common Chameleon 

 (Cham&leo vulgaris) (fig. 143), ranges round the eastern and 

 southern shores of the Mediterranean, and also extends into the 

 south of Spain. 



Order 4. SNAKES (Ophidia) 



Although at first sight there seems to be a great deal of 

 difference between snakes and lizards, careful examination 

 shows that there are important points of resemblance, and 

 some zoologists include the two groups in a single order, 

 Squamata, among the distinctive features of which are the 

 possession of well-marked overlapping scales, a transverse cloacal 

 opening, quadrate bone movably attached to the skull so as to 

 give a double jaw-joint, and simple lungs. 



