LIZARDS. 



33 



is entirely erroneous. Fine specimens of the South European 

 Scheltopusik, or Glass-Snake {Ophisaurus apus, 431) are exhibited. 



The so-called Gila Monster {Heloderma suspectum, 424, fig. 35) of Case 19. 

 Mexico and an allied species from New Mexico and Arizona, alone 

 constitute a family (the ffelodermatidce, or Poisonous Lizards) charac- 

 terised by the presence of recurved fang-like teeth loosely attached to 

 the lower jaw, which discharge poison through open grooves secreted 

 by special glands. The dentition is pleurodont, the tongue is cleft at 



Fig. 35. 



The Gila Monster (Heloderma suspectum) ; J nat. size. (No. 424-) 



the tip, and the bony plates in the skin are small, and communicate 

 the peculiar granular texture to the upper surface. The Gila 

 Monster is a creature of lethargic and nocturnal habits, crawling 

 about in the evening in search of worms, frogs, centipedes, and 

 Iguanas' eggs. Frogs are paralysed, if not killed, by the bite, which 

 is also dangerous to human beings, although rarely productive of death. 

 In captivity these Lizards eagerly break eggs and lap up the contents. 

 During the hot season they become torpid. 



A very rare Bornean Lizard (Lanthanonotus borneensis) is nearly 

 allied to the Helodermatidce, from which it is distinguished by the 



D 



