THE SNAKES OF BRITISH EAST AFRICA 55 
Family IX, — VIPEBIDAE. (Poisonous.) 
Sub-Family I. — Vi'perinae. 
Genus Causus — 
Bhombeatus. — Total length 2 feet 8§ inches. Tail 8 inches. 
Olive or pale brown above, rarely uniform, usually with a 
dorsal series of large rhomboidal or V-shaped dark-brown 
spots which may be edged with whitish ; usually a large dark 
A-shaped marking on the back of the head, the point on the 
frontal, and an oblique dark-edged streak behind the eye ; 
labials usually dark-edged ; lower parts yellowish- white or 
grey, uniform or the shields edged with black Found in 
Kavirondo, also in Limoru Road, near Nairobi. 
Besimus. Total length 1 foot 6J inches. Tail 1 foot 
8f inches. Greyish olive above, uniform or with curved 
Causus resimus. 
From Report of Wellcome Lab., Khartum, Vol. III. 
or chevron-shaped cross-bars pointing backwards ; uniform 
white underneath. Found at Ngetana, Mkonumbi, and Lamu. 
Defili'p'pii. Total length 1 foot 8f inches. Tail § inches. 
Grey or pale-brown above, vertebral region darker, with a 
series of large rhomboidal or V-shaped dark-brown markings 
on the occiput, the point on the frontal ; an oblique dark 
streak behind the eye ; upper labials black-edged ; yellowish- 
white beneath, uniform or with small greyish-brown spots. 
Found in Rabai. 
Genus Bitis. ( Puff Adder ) — 
Arietans. — Total length 5 feet 5 inches. Tail 6J inches. 
