428 



LOWER VERTEBRATES. 



The Helodeematidje includes the largest North American lizard, the Gila monster, 

 Heloderma suspectum. This animal, whose habitat is New Mexico, Arizona, and 

 the country lying southward, is, because of its poisonous nature, as well as from its 

 large size and peculiar ornamentation, a common object in the larger zoological collec- 

 tions and menageries, where it thrives on eggs, and at times wakes from its ordinary 

 stupor and is quite lively. In its native haunts it attracts attention by its strange 

 coloration, as it is of a deep black, ornamented with irregular blotches of orange, and 

 covered by a thick and rigid coat of small horny tubercles and scales. 



Though the more incredulous scientist has questioniad the character given this 

 animal by the superstitious Indians and Mexicans, who regard it with the utmost fear, 

 maintaining that it possesses venom of a most virulent nature, a test was recently 

 made by Dr. Shufeldt, which is of considerable interest. He says, in giving an account 



Fig. 246. — Heloderma horrida, Gila monster. 



of an animal at the National Museum : " It was in capital health and at first I handled 

 it with great care, holding it in my left hand, examining special parts with my right. 

 At the close of this examination I was about to return the fellow to his temporary 

 quarters, when my left hand slipj)ed slightly, and the now highly indignant and irri- 

 tated Helodei-ma made a dart forward and seized my riglit tliumb in his mouth, 

 inflicting a severe lacerated wound, sinking the teeth in his upper maxilla to the very 

 bone. He loosed his hold immediately, and I replaced him iu his cage, with far 

 greater haste, perhaps, than I removed him from it. 



" By suction with my mouth, I drew not a little blood from the wound, but the 

 bleeding soon ceased entirely, to be followed in a few moments by very severe shoot- 

 ing ])ains up my arm and down the corresponding side. The severity of these pains 

 was so unexpected, that, added to the nervous shock already experienced, no doubt. 



