THE PBINCIPAL 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 2-5) 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. contortrix (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 Eattle-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. 



