576 



The Living Animals of the World 



Photo by W. F. Dando, F.Z.S.] [Regents Park, 



ARIZONA HELODEEM (POISONOUS LIZARD). 



In the warted texture of its skin-surface the heloderm differs conspicuously from 

 other lizards. 



retrograde forms in which the hinder 

 limbs are entirely absent or the front 

 ones reduced to mere stumps. These 

 exceptional instances pave the way to 

 the family of the Amphisbasnas, in 

 which such or a still lower phase of 

 limb development represents the 

 normal condition. The Amphisbaenas 

 are remarkable for their worm-like 

 resemblance, and for the circumstances 

 that they live like earth-worms in 

 burrows, that their eyes are function - 

 less (being concealed beneath the skin), 

 and that they are without ears. Other 

 details of structure indicate a most 

 rudimentary condition of development, 

 and they consequently rank as the 

 lowest group in the Lizard series. 

 Another peculiarity of the Amphisbsenas is that, in place of scales, the skin of the body is 

 divided into square segments, which form symmetrical rings like those of worms. In addition 

 to this, these retrograde lizards possess the worm-like faculty of being able to move backwards 

 and forwards in their burrows with equal facility. It is from this peculiar property that theii 

 title of Ainphisbsena, signifying " moving both ways," is derived. The representatives of this 

 family, including between sixty and seventy species, are widely distributed, being found in 

 America, the West Indies, Africa, and also European countries that border the Mediterranean. 



While the Teguexins present resemblanfces in one direction with the Amphisbsenas, or 

 Worm-like Lizards, the higher or Monitor-lik* forms have much in common with the Typical 

 or True Lizards, of which two small but \Wl-known species the SAND- and VIVIPAROUS 

 LIZARDS are indigenous to the British Isles. All the members of the True Lizards, 

 numbering some hundred species, are inhabitants of the Old World, becoming scarce, however, 

 towards the far east of the Asiatic Continent. All possess shapely bodies and well-developed 

 limbs with five-toed feet, and are remarkable for the extreme activity of their move- 

 ments, and in many cases brilliant colouring. 



The varying individual shades of 

 the GREEN LIZARD'S brilliant emerald 

 body are almost infinite, no two being 

 quite precisely alike in this respect. 

 In some a yellower, in others a bluer 

 green predominates, while the females 

 and young are more or less mottled 

 or striped with brown. The under 

 surface of the body is usually a more 

 or less bright yellow, and the throat, in 

 the males more particularly, at the 

 breeding-season is frequently brilliant 

 blue. The more conspicuous colour 

 differences exhibited by this lizard 

 are, however, intimately associated 

 with the local habitat of the particular 



Photo by Scholastic Photo. Co.] [Parson's Green. race. Those indigenOUS to Spain 



WHITE MONITOR. and Portugal, for example, are more 



This and other allied species appear to be dead as they lie basking in the sun. or leSS Ornamented with OCellated Spots 



