184 
THK POISONOUS SNAKES OF THE ANOI.O-BGYPTIAN SUDAN 
Horned \'iper 
Plrythrea to the Capo of Good Hope and also from South Arabia; but as it is a snake of 
open plains and savannalis it has not been recorded from countries with thick forest, such 
as the Cameroons. 
Hoettger believes this snake to be an aquatic one, on account of its nostrils being turned 
directly upwards, and its feeding, especially, on frogs. This is certainly not the case in the 
Sudan and near Gondokoro, where it frequents the savannahs and even the hills far from 
any water and, accordingly, from frogs, which are more limited to the water (at least, in 
the dry season) than in Europe. 
We know several localities for this viper in the Sudan, as already enumerated in my 
pulilication on the Sudan reptiles. Hartmann found it in the Bejuda-Steppe, Ruppell, in 
Kordofan, Harno, at the Tura-El-Chadra and the Dalibed-Hanakhi; a specimen from the 
Sobat is in the Gordon College Museum, and another one, found by myself at Goz-Abu- 
Guma, in the Vienna IMuseum. No other of the eight species of Bifie probably occurs in 
the Sudan. 
Genus: Cerastes, Wagler 
Head, very distinct from neck, covered with small juxtaposed or feebly imbricate 
scales ; eye, moderate or small, with vertical pupil, separated from the labials by small 
scales ; nostril directed upwards and outwards. Body, cylindrical; scales keeled, in 2-3-35 
rows; dorsal scales forming straight longitudinal series, with club- or anchor-shaped keels, 
not extending to the extremity of the scale ; lateral scales smaller, oblique, pointing down¬ 
wards, with serrated keels ; ventrals with an olituso keel on each side. Tail, short; 
subcaudals in two rows. 
North Africa, Arabia, Palestine. 
Cerastes ctiruntits, Linnyeus 
Plate XX., lig. 2 
Horned Viper 
Boulenger, ('at. Bnahes, IIP, p. 502 
Anderson, “ Zool. Egypt., Rejit.,” p. 330, Plate XLVIII 
Fifteen to twenty-one scales across the front, from eye to eye ; a large, erect, ribbed, 
horn-like scale, often present above the eye ; 14-18 scales round the eye; 4-5 series of 
scales lietween the eye and the labials ; nostril in a single small shield, separated from its 
fellow’ by 0-8 longitudinal series of scales, from the rostral by two or three (rarely one) ; 
12-15 upper labials ; scales in 27-35 rows. Ventral, 130-165, with feeble lateral keel; 
subcaudals, 25-42 ; the posterior usually more or less distinctly keeled. Coloration, pale 
yellow’ish-brown above, uniform or with 4-6 regular series of round browm spots, the two 
middle ones sometimes confluent, forming cross-bars ; a more or less distinct oblique dark 
streak behind the eye ; lower parts, white ; end of tail rarely black. 
Total length, 720 mm. ; tail, 90 mm. 
Northern border of the Sahara, Egypt, Nubia, Arabia, Southern Palestine. 
The horned viper is restricted to the sandy parts of the Northern Sudan, and has not 
been found south of Senaar (Bruce) ; Anderson got it at Wady Haifa and Suakin ; 
Hartmann in the Bejuda ; specimens from Dongola (without horns) are in the Gordon 
College Museum. 
This, like the following species, is admirably adapted for life in sandy, desert localities. 
The serrated keels of lateral scales acting as sand ploughs, the snake can, by curious strong 
movements of its body-muscles, rapidly disappear before the eyes of the spectator by 
covering itself with sand and sinking vertically down in it without moving its body as a 
