478 REPTILES. 



hemisphere. Examples :—^^awo y Draco, with the skin extended on 

 long prolongations of five or six posterior ribs ; Chlamydosaurus, an 

 Australian lizard, with a large scaled frill around the neck ; Moloch, 

 another Australian form bristling with sharp spikes. 



The Iguanas (Iguanidos) are pleurodont lizards, represented in the 

 warmer parts of the New World. Examples: — Iguana, an arboreal 

 lizard, with a large distensible dewlap ; Amblyrhynchus or Oreocephalus 

 cristatus, a marine lizard confined to the Galapagos Islands ; Basiliscus, 

 in S. Mexico, with none of the marvellous qualities of the mytho- 

 logical basilisk ; Anolis, the American chamoeleon, with powers of 

 rapid colour-change ; Phrynosoma, the American " horned- toad," with 

 numerous horny scales. 



The slow-worms (Anguidse), are limbless lizards, with serpentine 

 body, long tail, rudimentary girdles and sternum. The British species, 

 Anguis fragilis, is neither blind nor poisonous ; the tail breaks very 

 readily; the young are hatched within the mother. The American 

 "glass-snake " — Opheosaurus ventralis — is in many ways like our slow- 

 worm. 



The poisonous Mexican lizard ( Helodertna suspectum) measures over 

 a foot in length, and is covered with bead-like scales. Its bite is 

 poisonous, and rapidly fatal to small Mammals. It is interesting to 

 find poisonous powers like those of many serpents exhibited by this ex- 

 ceptional lizard. 



The water-lizards (Varanidje) are large semi-aquatic forms of carni- 

 vorous habit, most at home in Africa, but represented also in Asia and 

 Australia. The Monitor of the Nile, Varanus niloticus, may attain 

 a length of five or six feet, and is noteworthy because of its fondness for 

 the eggs and young of Crocodiles. 



The family Teiidas includes many New World pleurodont lizards, 

 mostly terrestrial in habit, for examples Teius tegtiexim, the varie- 

 gated lizard of tropical Brazil, sometimes measuring five feet in length ; 

 Ameiva dorsalis, the common ground-lizard of Jamaica. 



The Amphisbsenidre are degenerate subterranean lizards, without 

 limbs, with rudimentary girdles, with no sternum, with small covered 

 eyes, with hardly any scales. The sooty Amphisb^na {A.fuliginosa), 

 at home in the warmer parts of S. America, is the commonest species. 



The Lacertidae are Old World acrodont lizards, such as Pseudopus 

 (Europe and S. Asia), Lacerta viridis, the green lizard of Jersey and S. 

 Europe, L. agilis, the British grey lizard, L. muralis abundant about 

 ruins in S. Europe, Z. or Zootoca vivipara, the British scaly lizard. 



The Scincidae are common in tropical countries, e.g., Scincus, 

 Cyclodus, Seps, Aconlias (without limbs), Oligosoma (abundant in the 

 Southern States of America), Eumeces (common in America and else- 

 where). 



The Chama^leons (Chamceleontidse) are very divergent lizards, mostly 

 African. There is one genus Ckamaleo. The head and the body are 

 compressed ; the scales are minute ; the eyes are very large and mov- 

 able, with circular eyelids pierced by a hole ; the tympanum is hidden ; 

 the tongue is club-shaped and viscid ; the digits are divided into two 

 sets, and well-adapted for prehension ; the tail is prehensile ; the power 

 of colour-change is remarkably developed. 



