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Oisr THE EHYSIOaNOMY OF SEEPENTS. 
II.-VENOMOUS SERPENTS 
Form the second grand division of Ophidians. They are 
all provided with a murderous tooth or fang^ fixed on the 
maxillary bone ; of which the size is so reduced, that it 
rarely carries any other tooth than the fangs. This divi- 
sion naturally arranges itself into three groups or Families. 
Coluhriform Venomous Serpents form the first of these, 
including all those venomous Ophidians that by their 
form approach the non- venomous terrestrial serpents, to 
which they have usually a very striking resemblance, and 
are often distinguishable from them by no external sign, 
except the thickness of their muzzle. They have the 
trunk elongated, the tail short, massive, and conical, the 
eyes a little voluminous, and the pupil orbicular, the nos- 
trils open and lateral. Their scales are large, lozenge- 
shaped, and almost always smooth. Their head is invested 
with plates like those of the genus Coluber ; the rostral is 
sutficiently developed, while the frenal is ordinarily want- 
ing. The venomous apparatus is usually little developed ; 
the maxillary bone is long, and often armed with teeth 
placed behind the fangs, which last are short but strong, 
and provided with a groove uniting the orifices ; the lower 
jaw, with its suspensory pieces, is little developed. These 
Ophidians inhabit the hot countries of both worlds ; they 
are not found in Europe, and only form three genera. 
FLAPS. 
This genus has a cylindrical trunk, very slender, and of 
equal thickness throughout, surrounded usually with 15 
rows of broad and smooth scales ; the head elongated, and 
little distinct from the trunk; tints, for the most part, 
vivid and beautiful. They frequent wooded places, or 
coverts of grass, and seem to shun arid soils. They inha- 
