THE PRINCIPAL SPECIES OF POISONOUS SNAKES 
slenderness of the fangs, the narrowness of their canals, and the 
considerable distance between the fangs and the anterior opening 
of the mouth, must necessarily render the bites of these snakes less 
serious and of rarer occurrence. 
II.— VIPERID.—CROTALIN &. 
The. Solenoglypha 
are infinitely more for- 
midable in the two 
divisions of the New 
World.. They are re- 
presented by a large 
number of species, some 
of which are feared in 
consequence of their size 
and ferocity, even more 
than on account of the 
deadliness of their 
venom (fig. 67). 
The American CRo- 
TALINÆ are divided into 
two groups :— 
The first of these 
comprises snakes not 
provided with the cau- 
dal appendage, which is 
characteristic of the 
Rattle-Snakes. It con- 
sists of two genera :— 
(a) Ancistrodon. 
(b) Lachesis. 
+} 
Fic. 67.—HEAD AND SKULL OF Crotalus horridus. 
The second group includes only those snakes the tails of which 
are terminated by the scaly appendage known as the “ rattle.” 
109 
