THE PRINCIPAL SPECIES OF POISONOUS SNAKES 73 
Total length, 350 millimetres; tail 30. 
Habitat : Cape of Good Hope. 
(5) B. cornuta (fig. 38).—Nostrils opening upwards and out- 
wards. Head covered with small, imbricate, strongly keeled scales ; 
2—5 raised scales, like horns, above each eye ; 12—14 scales round 
the eye; 12—15 supralabials ; 2—3 infralabials. Scales on the body 
keeled, in 25—29 rows; 120—152 
ventrals ; 18—-36 subcaudals. 
Colour grey or reddish - brown, 
with black spots, edged with white 
and arranged in 3 or 4 longitudina 
series; a dark, oblique streak from 
the eye to the mouth; belly yellow 
or brown, uniform or spotted. 
er Fig. 38.—Bitis cornuta. 
Total length, 510 millimetres ; (After Duméril and Bibron.) 
Eaton 
Habitat : Cape Colony, Namaqualand, Damaraland. 
(6) B. caudalis—Nostrils opening upwards and outwards. 
12—16 scales from one eye to the other across the head; above 
each eye a single, erect, horn-hke scale ; 10—16 scales round the 
eye; 10—13 supralabials; 2—3 infralabials. Scales on the body 
in 22—29 rows, strongly keeled; 112—153 ventrals ; 18—33 sub- 
caudals. 
Colour reddish or sandy-grey, with 2 series of brown spots with 
light centres, and frequently a vertebral series of narrow spots ; 
belly dull yellow, uniform, or with small black spots on the sides. 
Total length, 360 millimetres; tail 25. 
Habitat: South-west Africa, from Angola to Namaqualand. 
(7) B. gabonica (Gaboon Viper, or River Jack Viper).—Nostrils 
directed upwards and outwards. Head covered with small, 
moderately keeled scales, smallest on the vertex, 13—16 from eye 
to eye; 15—19 scales round the eye; a pair of erectile, triangular, 
nasal ‘“ horns,” consisting of sometimes tricuspid shields, between 
the supranasals ; 13—16 supralabials; 4—5 infralabials. Scales 
