SPECIES OF HELODERMA 
appear to be two distinct kinds of heloderma, viz. 
H. suspectum and H. horridum. One epithet is good, 
the other bad. It is truly “horrid” in the applied 
as well as in the literal sense of that adjective, for 
the skin is roughened with warty scales underlain by 
bony nodules. “ Suspectum” is too dubious an ad- 
jective; for this lizard is not merely suspected but 
known to be poisonous, being in fact the only lizard 
which has this qualification. It was thought some 
little time ago that the rare Lanthanonotus of Borneo 
was also poisonous ; but recent study has proved that, 
while related to Heloderma, it lacks the grooved teeth 
of the latter. Experiments tried with Heloderma as 
the main actor with the subsidiary parts played by 
various frogs and guinea pigs has satisfied every one 
that this lizard does bite with a poisoned effect ; more- 
over the salivary glands, or rather some of them, are 
furnished with several ducts which open in close apposi- 
tion to the grooved teeth ; along the grooves run the 
poison which is thus necessarily injected into the wound 
made by the teeth. In fact, the gila monster poisons 
precisely in the same fashion as the venomous colubrines, 
those non-viperine snakes which are poisonous. On 
the other hand, the courageous Dr. Shufeldt allowed 
himself to be bitten by one of these lizards, but ex- 
perienced no serious inconvenience “‘ beyond the ordi- 
nary symptoms that usually follow the bite of an 
enraged animal.’’ Like most lizards this animal is 
lethargic and melancholy in appearance in captivity. 
It seems indeed to have fewer and shorter repetitions of 
those periods of briskness which even the most seden- 
tary of lizards show at times. It can, however, be 
roused, and then its wrath is terrible. Under these 
circumstances, observes Dr. Shufeldt, “the animal 
quickly rears its body from the ground by straightening 
out its limbs, wheels about, opens its mouth widely, 
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