THE PRINCIPAL SPECIES OF POISONOUS SNAKES 111 
rivers, and feeds upon fish, but also devours small warm-blooded 
animals. The Creoles call it the Congo Snake. It is fairly 
common in the environs of New Orleans. In summer time it 
conceals itself in the branches of trees at the edge of the water. 
It frequents inundated rice-fields, and is a terror to the blacks. It 
attacks readily, and opens its jaws some seconds before it bites. 
(2) A. bilineatus.—Snout obtusely pointed. Scales more or 
less strongly keeled, in 23 (rarely 25) rows; 135—141 ventrals; 
52—64 subcaudals, anterior single, posterior divided. 
Colour dull yellow or reddish-brown, with more or less distinct 
darker cross-bands, or alternating transverse blotches, with yellow 
edges; a vertical yellow line on the rostral shield, and a fine 
yellow line round the snout; belly brownish or blackish, with 
white spots. 
Total length, 1,100 millimetres; tail 200. 
Habitat: Mexico, Guatemala, Honduras. 
(3) A. contortrir (The Copper-head).—Snout rounded or trun- 
cate. Scales strongly keeled, in 23 (rarely 25) rows; 145—155 
ventrals ; 31—-52 subcaudals, anterior single, posterior divided. 
Colour dull yellow or reddish-brown, with dark brown or 
brick-red cross-bars ; these bars are sometimes interrupted on the 
vertebral line, and form alternating triangles; belly yellow or 
reddish, more or less spotted with grey or brown. 
Total length, 990 millimetres ; tail 110. 
Habitat: North America, from Massachusetts and Kansas to 
Northern Florida and Texas. 
This snake is often more dreaded than a Rattle-Snake. 
(b) Lachesis. 
In Lachesis the caudal rattle is represented by a series of 10 
or 12 rows of spiny scales, which are slightly hooked at the tips. 
The head is covered with small shields or smooth or keeled scales, 
with or without apical pits. The maxillary is much reduced; the 
transverse or pterygoid bone, on the contrary, is greatly developed. 
