66 VENOMS 
long tooth at the end of each ramus of the mandible. Head 
narrow, elongate ; eye moderate, with round pupil; nostril between 
two shields. Body shghtly compressed; scales smooth, narrow, 
very oblique, in 13—23 rows; ventrals rounded. Tail long ; sub- 
caudals in 2 rows. 
(1) D. viridis.—211—295 ventral scales ; 107—119 subcaudals. 
Colour uniform olive-green. Shields on the head edged with 
black; lips yellow; belly and tail yellow, with scales and shields 
bordered with black. 
Total length, 1,830 millimetres ; tail 460. 
Habitat: West Africa, from the Senegal to the Niger; St. 
Thome Island. 
(2) D. gamesonit.—Coloration as before. Scales in 15—19 rows 
(19—921 on the neck); 210—235 ventrals; 99—121 subcaudals. 
T'ail sometimes black. 
Total length, 2,100 millimetres; tail 560. 
Habitat: West Africa, from the Niger to Angola; Central 
Africa. 
(3) D. angusticeps (The Mamba).—202—270 ventral scales ; 
99—121 subcaudals. 
Colour green, olive, or blackish, uniform ; belly yellowish or pale 
ereen; caudal scales and shields not bordered with black. 
Total length, 2,000 millimetres ; tail 430. 
Habitat: West Africa, south of the Congo; Central Africa, 
East Africa, Transvaal, Natal. 
(4) D. antinorii.—Scales in 21—23 rows; 248 ventrals; 117 
subeaudals. Colour olive on the back, yellowish on the belly. 
Total length, 2,690 millimetres ; tail 545. 
Habitat: Abyssinia. 
II.—VIPERIDZ. 
The African Viperide all belong to the Subfamily Viperine, of 
which the following are the seven principal genera :— 
