THE PRINCIPAL SPECIES OF POISONOUS SNAKES 117 
(9) L. ammodytoides.—Snout turned up, in the shape of a wart ; 
two series of scales between the eye and the Jabials; scales in 23 
or 25 rows, very strongly keeled ; 149—160 ventrals; 30—38 pairs 
of subcaudals. 
Colour pale brown, with large brown black-edged spots or 
cross-bands, which may alternate and form a zigzag band; a dark 
streak behind the eye; belly yellowish, spotted with brown. 
Total length, 460 millimetres ; tail 55. 
Habitat : North-eastern Patagonia and Argentina. 
(10) L. xanthogrammus.—Head elongate, snout short: scales 
n 27 rows, feebly keeled; 196 ventrals; 54 subcaudals. 
Colour very dark olive, with a yellow zigzag line on each side 
from the head to the base of the tail; the angular parts enclose 
rhombic spaces and lateral triangles ; top of head black, with a 
pair of undulating yellow bands from the nape to the vertex ; 
a bright golden band round the snout: labials bright yellow; 
ventral shields black, paler in the que. with polo triangular 
spots at their extremities. 
Total length, 1,530 millimetres; tail 190. 
Habitat : Eastern Ecuador, Andes of Colombia. 
(11) L. castelnaudi—Head narrow and elongate ; scales on the 
head smooth or feebly keeled, small ; body-scales strongly keeled, 
in 25 or 27 rows; 230—253 ventrals ; 72—83 subcaudals, all or 
majority in a single row. 
Colour greyish or brown, with dark or light- edged spots or 
cross-bands; head with dark spots, one of which occupies the 
middle of the snout ; a dark band from the eye to the angle of the 
mouth ; belly brown or blackish, spotted with yellow. 
Total length, 1,220 millimetres; tail 180. 
Habitat: Brazil, Ecuador, Eastern Peru. 
(12) L. nummifer.—Snout broad, rounded ; 10 or 11 supralabials : 
scales in 23—27 rows, strongly keeled; 121—134 ventrals: 26—36 
subcaudals, all or the majority single. 
Colour pale brown, with a dorsal series of rhomboidal spots, 
