The Poisonous Snakes of the Anolo-Eoyftian Sudan 
BY 
Doctok Fuane Weknek 
As far as we know at present, the Egyptian Sudan is inhabited by eight different 
species of poisonous snakes, two of whicli are restricted to the desert region of the North 
(Wady Haifa to Kordofan and Senaar), four to the tropical parts, the rest being probably 
found throughout the whole country, wherever the conditions of life are favourable to them. 
None of these eight species is exclusively a Sudanese one ; all are widely distributed 
over a very great part of Africa, and two of them are also found in Western Asia, one 
even in India. 
The Sudanese poisonous snakes belong to two groups of the modern systematic 
division of snakes, as established by Boulenger, to the colubrine snakes and to the 
true vipers. 
The general aspect of the poisonous colubrine snakes is that of one of the harmless 
species of the country. The head is covered with large symmetrically-arranged plates, 
and is not, or is very slightly, dilated behind, thus differing from what is generally known 
of the true vipers, the head of which is more or less triangular seen from above. The 
pupil is round; the scales of the body and tail as well as all the plates of the head 
are perfectly smooth; the body and tail are elongate, and neither the head nor the tail are 
distinctly separated from the body. 
All the characters enumerated above are found equally in the non-venomous colubrine 
snakes; and if we wish to be quite sure of the venomous or non-venomous character of such 
a colubrine snake it is necessary to examine its dentition, which is characteristically 
different in the three large groups of colubrine snakes. We can distinguish :— 
AglijpJious colubrine snakes, the teeth of which are all perfectly solid and not grooved 
at all. A dozen of the Sudanese species of snakes belong to this group. 
Opisthoglyphotis colubrine snakes (Plate XX., fig. 3). In this group the last tooth or teeth 
in the upper jaw are more or less enlarged, and are provided with a longitudinal groove on 
the anterior aspect, beginning at the base and ending before the point of the tooth. This 
group is likewise represented by about a dozen species. 
Proteroglyphous colubrine snakes (Plate XVII., fig. 1). Here the prolonged and grooved 
teeth (two) are placed quite to the fore in the upper jaw, which is, in the Sudanese species, 
considerably reduced in length, but is always longer than broad. It is not absolutely 
necessary to examine the teeth in the two species of colubrine proteroglyphous snakes of the 
Egyptian Sudan. Both these belong to the highly poisonous genus Kaja, widely known by 
the curious power snakes of this genus have of flattening their necks horizontally and raising 
the forepart of their bodies, thus sujiporting the dilated neck. Living specimens irritated 
in any manner—especially when prevented from escaping —very soon expand their hoods, 
and prepare themselves to bite, often bending the erected forepart of the body so far 
backward that it nearly rests on the back. The next moment the snake may protrude 
its head rapidly, and the energy with which this is effected is so great that a considerable 
part of the body may be projected with it. This gives an impression as if the snake 
would directly jump at the offender, but such is never really the case. How a Aoja 
Colubrine 
snakes and 
vipers 
Varieties of 
colubrine 
snakes 
