THE BEADED LIZARDS 
'°5 
The Beaded Lizards. 
BY ALLEN S. WILLIAMS. DIRECTOR REPTILE 
STUDY SOCIETY OF AMERICA. 
North America has the distinction, 
proud or otherwise, of having the only 
definitely poisonous lizard in the world. 
This is a southwestern genus of two 
species and is a habitant of arid re- 
gions, practically a type of desert life. 
These close cousins are termed beaded 
lizards, and an inexplicable thing about 
them is that they exist in widely sepa- 
The northern form, “pink, or red- 
dish yellow and black, head mottled 
with the lighter hue.” Southern spe- 
cies, “pale yellow and black, head en- 
tirely black.” I he skin is covered with 
closely set beadlike tubercles, impart- 
ing a remarkable similarity to Sioux 
Indian bead work. The form of these 
lizards presents a stout body with short 
limbs and a short, thick, rounded tail. 
An adult Gila monster attains a length 
of about twenty inches, while the 
THE GILA MONSTER. 
rated localities. The northern species 
inhabits Arizona and New Mexico, and 
is there best known under its formid- 
able cognomen of “The Gila Monster.” 
This name is derived from the long and 
crooked Gila River and the name ob- 
tains the Spanish pronunciation, with 
the G sounded as H, so “heelah” is the 
proper sound. 
The generic scientific term for this 
family is Helodermatidae, and the Gila 
monster is termed Heloderma suspect um , 
while its southern cousin, living far 
down in southwestern Mexico and 
northern Central America, is termed 
Heloderma horridum. Dr. Raymond Lee 
Ditmars, Curator of the New York 
Zoological Park, in “The Reptile 
Book.' thus succinctly specifies the 
difference in appearance between the 
two species so far as coloration is con- 
cerned : 
beaded lizard grows larger. Ditmars’s 
own measured record being twenty-six 
and one-half inches. 
In our own “Southwest” the popular 
view of these animals is that they are 
to man “deadly poison.” The natives 
take delight in exaggerating the effects 
of the bites of these animals, although 
they probably believe much of what 
they tell. The late Edward Drinker 
Cope, in many respects America’s fore- 
most herpetologist, christened the Gila 
monster Heloderma suspect um because at 
that time, maybe forty years ago, the 
creature was only resting under sus- 
picion of possessing poisonous poten- 
tialities. Dr. S. Weir Mitchell was a 
pioneer investigator who early defi- 
nitely established the fact that this 
weird looking lizard really is venom- 
ous. Since then this subject has been 
thoroughly investigated and a sum- 
