THE rOISONOUS SNAKES OP THE ANGLO-EG YPTI AN SUDAN 
185 
whole. It has its holes mostly between the roots of low desert plants ; feeds especially 
on small mammals (mice), and is, like probably all true vipers, capable of being tamed, so 
far as to take food from its master’s hand. 
The other species of Cerastes {('. vipi'ra, L.) does not enter the Sudan, being restricted 
to North Africa proper. 
Genus : Erliis, Merrem 
Head very distinct from neck, covered with small imbricate scales; eye moderate, 
with vertical pupil, separated from the labials by small scales; nostril directed upwards 
and outwards. Body cylindrical; scales keeled, in 27-37 rows ; dorsals forming straight 
longitudinal series; lateral scales smaller, oblique, pointing dowmwards, with serrated 
keels ; ventrals roimded. Tail short; subcaudals single. 
Africa, north of the Equator ; Southern Asia. 
Kchis cariiiatnt:, Schneider 
Plate XVII., fig. 2 
Boulenger, (ktf. Snakeii, III., p. 505 
Anderson, “ Zool. Egypt.,” I., p. 336, Plate XLIX. 
Head covered with small, more or less strongly keeled, scales ; a narrow supra-ocular 
sometimes present; two (rarely three or one) series of scales between the eye and the 
labials ; anterior nasal shield in contact with the rostral; 10-12 upper labials ; scales in 
27-37 rows. Ventrals, 132-192 ; subcaudals, 21-48. Pale buff, greyish, reddish, or brown 
above, with one or three series of whitish, dark-edged spots; a zigzag dark and light band 
may run along each side; a cruciform or ari'ow’ or Y-shaped whitish marking often present 
on the head; lower parts wdiitish, uniform, or with brown dots or with small round 
black spots. 
Total length, 720 mm. ; tail, 70 mm. 
Desert or sandy districts of Africa, north of the Equator ; Southern Asia, from 
Transcaspia and Arabia to India. 
This small and widely distributed viper is known in the Sudan only from the northern 
parts; from Suakin and Durrur by .1. Anderson; from Khartoum, Dongola and Kordofan 
(MazrCib) by A. L. Butler. But as it ranges southw'ards to Togo and Somaliland, there is 
no doubt that it will be found also in the Upper Nile valley. It is much feared everywhere, 
and known as “ Efa ” in North Africa and as ” Phoorsa ” in North India. It feeds 
principally on small mammals and birds. The second species of this genus, 1<J. cvloratuf!, 
Giinther, is restricted to Palestine, Arabia and the Bed Sea Coast of Egyj)t, and may be 
found also in the Sudan, though I think that both species are mutually exclusive. 
AI'I’ENDIX 
The snakes called “ Opisthoglyphous,” having the last teeth of the upper jaw more or 
less enlarged and longitudinally grooved on the front surface, are also poisonous in different 
degrees, according to genus. But only a few species reach such dimensions as to be able 
to bite a man successfully—the poison-fangs being so far back in the mouth that only small 
parts of the human body like a finger can come within their reach. Moreover, the poison 
of most of them does not act perceptibly on man. Practically only the genus Fuaiiuiiophis, 
and, among its four species, only /'. sihiJdiis, L. (Plate XX., fig. 3), would be considered as 
venomous. In the Upper Nile Valley this snake reaches a length of about five feet, and 
may be easily identified on account of its large eyes with round j)upils, the very elongate 
loreal, and the prominent supra-ocular. As it is Ijy no means aggressive, but takes rapidly 
