NUMBERS AND DISTRIBUTION. 217 
Supraocular region usually with horn-like scales ; 
Sab cwadals: in females, small and _ scale- like, 
more or less distinctly keeled. Two or more 
supraorbital horns .. aie Sis be .. Buitis cornuta. 
Supraorbital region with only one horn-like erect scale. 
Sometimes it is not present ac ee .. Bitis caudalis. 
I. BITIS ARIETANS. Puff Adder; Pof Adder. 
Synonyms—Vipera arietans ; Cobra lachesis ; Clotho arietans ; Echidna 
arietans. 
Colour—Yellow, pale brown, or orange above, marked with regular 
chevron-shaped dark brown or black bars pointing backwards, 
or black with orange or yellow markings; a large dark blotch 
covering the crown, separated from a smaller interorbital blotch 
by a transverse yellow line; an oblique dark band below, and 
another behind the eye; yellowish white beneath, uniform, or 
with small dark spots. 
Average length—2z feet 6 inches to 3 feet. Attains a length of 5 feet. 
Distribution—All parts of South Africa. Northwards through Tropical 
Africa to Arabia. 
2. BITIS PERINGUEYI. Peringuey’s Adder. 
Synonym—Vipera pervingueyt. 
Colour—Pale buff or greenish olive above, with three longitudinal 
series of grey or blackish spots, the outer ocellar, enclosing a 
white centre; head sometimes with a trident-shaped dark 
marking on the crown, followed by a cross and two large markings 
on the occiput ; whitish beneath, with small dark spots. 
Average length—z foot. 
Distribution—Kalahari ; German South-West Africa; Angola. 
3. Biris aTropos. Berg Adder. 
Synonyms—Coluber atropos ; Cobra atropos ; Vipera atropos ; Clotho 
atropos ; Echidna atropos. 
Colour—Brown or greyish brown above, with four longitudinal series 
of large dark brown, black and white edged spots, formed by 
the breaking up into two of the two series of sub-circular spots ; 
a continuous or interrupted whitish streak running between, 
and dividing the spots on each side of the back, and another 
lower down on the sides; two large dark markings on the head, 
from the nape to between the eyes; an oblique, light, dark- 
edged streak from behind the eye to the mouth; belly grey or 
brown, spotted with darker. 
Average length—1 foot 6 inches. 
Distribution—Both provinces of Cape Colony; Basutoland; Griqua- 
land; Orange River Colony; Natal; Zululand; Transvaal. 
(Mountainous regions, as its name implies.) 
4. BiTIs INORNATA. The Cape Puff Adder. Kaap Pof Adder. 
Synonyms—Echidna inornata ; Vipera atropoides ; Vipera inornata. 
Colour—Variable. 
A. Dark yellowish-brown above, with faint traces of darker markings, 
brownish-yellow beneath, with a few dark dots; head marbled 
with dark brown. 
B. Brown above, with two dorsal series of dark brown, black-edged 
spots. 
C. Reddish brown above, marked as in Bitis cornuta. 
Average length—18 inches. 
Distribution—Both provinces of Cape Colony. (Very uncommon.) 
