114 VENOMS 



hammer, and quickly draws back again. When verj' excited, it 

 resumes its position and strikes afresh. It never becomes tame, 

 but is capable of living a fairly long time in captivity. I have kept 

 a number of specimens of it for more than two years, caged in my 

 laboratory. 



(3) L. atrox (Labaria). — Closely resembling L. lanceolatus, 

 but bulkier ; the enormous head is armed with powerful fangs, 

 which are often more than a centimetre in length ; 7 supralabial 

 shields ; scales in 25 — 29 rows, strongly keeled ; 161 — 216 ventrals ; 

 47 — 73 pairs of subcaudals. 



Colour brown, with dark cross-bands or triangular blotches, with 

 the apices adjacent on the vertebral line ; a dark streak from the 

 eye to the angle of the mouth ; belly yellowish-white, speckled with 

 brown, or brown spotted with yellowish-white. 



Total length, 1,110 millimetres; tail 180. 



Habitat : from Central America to Peru and Northern Brazil. 



(4) L. pulcher. — Two postocular shields and a subocular, 

 separated from the labials by one series of scales : 7 supralabials ; 

 scales in 21 or 23 rows, strongly and tubercularly keeled : 156 — 172 

 ventrals ; 58 — 64 pairs of subcaudals. 



Colour olive-grey, with brown, light-edged cross-bands, which 

 are continuous or broken on the vertebral line ; a light streak 

 from the eye to the angle of the mouth ; belly covered with minute 

 confluent brown markings, with darker and lighter spots on the 

 sides. 



Total length, 685 millimetres ; tail 115. 



Habitat : Andes of Ecuador. 



(5) L.microphthalmus. — Snout short, rounded ; eyes very small ; 

 7 supralabials, of which the third and the sixth or seventh are 

 the largest ; scales in 23 rows, dorsals tubercularly keeled ; 159 — 

 161 ventrals; 62^ — 55 subcaudal pairs. 



Colour yellowish-brown or pale olive on the back, with dark 

 brown triangles on the sides ; posteriorly, the united triangles 

 form cross-bands ; a yellowish band from the eye to the side of 

 the neck ; belly dark brown with yellowish spots. 



