CHAPTER XIX: THE BEADED LIZARDS 

 FAMILY HELODERMATID^E 



A Family Composed of but Two Species The Gila Monster and the 

 Mexican Beaded Lizard Both of the Genus HELODERMA 

 Descriptions of the Species Their Habits 



HEAVY-BODIED, vividly marked, and with skin possessing 

 closely set, bead-like tubercles, the two species comprising the 

 family Helodermatidce are quite unique in form and thus easily 

 distinguishable from the other North American lacertilians. 

 They are, moreover, poisonous, being provided with grooved 

 fangs, which appeal much in their make-up to the poison conduct- 

 ing teeth of those serpents belonging to the division Opistho- 

 glypha. 



These creatures are the only known poisonous lizards 

 inhabiting the New World. One is confined to southern Ari- 

 zona and New Mexico; the other is found in western Mexico 

 and northern Central America. The latter species really occurs 

 far south of the limits embraced by this work, but it is included 

 in order to present a perfect outline of this family. 



Considerable has appeared in print concerning the poisonous 

 nature of the Beaded Lizards. Different opinions vary to a 

 great degree. Some writers allege that they are but mildly 

 poisonous, with a venom but slightly dangerous to mankind, 

 and these authors are usually men of technical knowledge, but 

 unfortunately given to theory after the examination of alco- 

 holic specimens. Other, and more popular writers, who have 

 actually observed the lizards in the wild state and noted their 

 actions upon capture, declare them very poisonous. And yet 

 there are others, and among them scientific men, who have 

 scoffed at the idea of these reptiles being in any way venomous. 

 Similar assertions have been frequent in relation to certain 

 snakes that are actually dangerous simply because persons 

 bitten by these snakes have suffered no ill effects beyond a few 

 superficial lacerations produced by the teeth a condition 



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