XII HELODERMATIDAE LANTHANOTIDAE 54 1 



in length. The animal, stout, depressed, thick -tailed, looks 

 rather repulsive when it squats down in its usual lethargic way. 

 The whole skin is blackish brown and yellow or orange, these two 

 " warning " colours being distributed unevenly, except on the 

 thick, peculiarly-shaped tail, where they are arranged in alternate 

 rings. The specific differences are rather imaginary. The New 

 Mexican form is supposed to be more orange and yellow than black, 

 with a somewhat smoother skin and with shorter toes and tail. 

 The " Gila Monster " inhabits dry localities, spends most of 



Fig. 137. — Heloderma susjxctum (the Gila Monster). x i. 



the daytime in concealment between the roots of trees, and crawls 

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

 the eggs of large lizards. Frogs are probably paralysed or killed 

 by the bite which, although not so dangerous as that of poisonous 

 snakes, is effective enough to produce severe symptoms even on 

 man, and a few cases of death of people who had been bitten are 

 on record. In captivity they are very partial to eggs, which they 

 break and then lap up. During the dry and' hot season they 

 aestivate. 



Fam. 7. Lanthanotidae. — Lanthanotus horneensis, of which 

 only two specimens are known, one in the Vienna Museum, the 



