32 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



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with a white edge, and a large A-shaped mark on the back of head; lips bordered 



black; belly yellowish or gray. Length 2 to 2.5 feet. Tropical and central Africa, 

 Gambia, Cape. 



Causus resimus. 



Snout prominent and more or less turned upward. Color olive-gray above, 

 uniformly white on belly. Length 1.5 feet. Central and eastern Africa, Angola. 



Causixs defilipii. 



Snout prominent, more or less turned upward. Color gray or pale brown above, 

 with a series of v-shaped, brownish-black, rhomboid speckles; large A-shaped speckle 

 on rear of head; dark oblique line from rear of eye; belly yellowish. Length 

 about 1.2 feet. Central and eastern Africa, Transvaal. 



Causus lichtensteinii. 



Snout obtuse; scales in 15 rows, the subcaudals in single row. Color dark gray 

 with indistinct marks. Western Africa, Gold Coast, Congo. 



Genus BITIS Gray.i 

 Head very distinct from neck, covered with imbricate small scales; eyes rather 

 small, with vertical pupils. Nostrils directed upward or upward and outward, 

 pierced in a single or divided nasal, with a deep pit or pocket above, closed by a 

 valvular, crescentic supranasal. The postfrontal bone is much larger than that in 

 Vipera. Scales keeled, in 29 to 41 rows; subcaudals in two rows. Tail very short. 



Bitis arietans. (Plate 13, d, e; plate 14, c.) 



The "puff adder" has the nostrils on the upper surface of snout. Body very 

 thick, tail short. Head large and triangular. Color yellow or orange with chevron- 

 shaped, large, oblique, black crossbars and an oblique band from rear of eye; belly 

 either all yellow or speckled with small black points. It is hard to see this viper 

 when it is lying on sand, or stony ground; the under parts are sometimes whitish. 

 It is very slow, and trusts to not being discovered when lying in the dry grass; 

 when approached it inflates the body and hisses loudly with a puffing sound, 

 watching the enemy with raised and characteristically bent head and neck; but it 

 bites only when actually touched or attacked. The effect of the bite is very dan- 

 gerous.^ Its prey consists chiefly of smaU mammals, which it hunts during the night. 

 Length about 4 to 5 feet. The whole of Africa, excepting northern coasts, from 

 southern Morocco, Kordofan, and Somaliland to the Cape of Good Hope, and 

 southern Arabia. 

 Bitis peringueyi. 



Color olive-gray, with 3 longitudinal series of blackish or gray speckles. Length 

 about I foot. Angola and Damaraland. 



Bitis atropos. 



Color brown or brownish-gray, with 4 longitudinal dark series of black and white 

 dots; belly gray or brown. Length up to 1.5 feet. Cape of Good Hope. 



Bitis inomata. 



Eyes smaller than in atropos. Length up to 1.5 feet. Cape of Good Hope. 



Bitis comuta. 



Nostrfls high and outward. Head covered with small imbricated scales, strongly 

 keeled; 2 to 3 scales alongside the eyes become so elevated as to appear like horns 

 at upper inner corner of eye on each side. Color gray or brownish-red with black 



1 Echidna. 



2 The natives of southern Africa claim that this viper can jump so high as to reach a man on horse- 



back. The Hottentots hunt it to get its head, which is used by them to prepare a poison for 

 arrows, by mixing the pulp of the crushed head and a certain plant juice. 



