268 THE EEPTILES OF EGYPT. 
and small spots margined more or less with black, producing short black lines, and 
some of the scales around the spots pale coloured ; the angle of every third or fourth 
ventral with a dusky spot, alternating with the lateral spots and prolonged on to the 
tail, or the ventrals immaculate. A more or less narrow black band along the side of 
the neck, corresponding in position to the lateral lines of the sides ; a broad dark 
brown band from behind the eye to the angle of the mouth. Margins of labials dusky. 
Upper surface of the head reticulated and spotted with dark brown, or entirely black 
or nearly so. Under surface yellowish, immaculate. 
It attains to 1340 millim. in length, of which the tail forms 252 millim. 
This species is widely distributed over the Nile valley, and is one of the most common 
snakes of the country. It is equally prevalent in the Eastern Sudan (Suakin District), 
and is indeed spread over Northern Africa to the Algerian Sahara. It is also found 
in Arabia, Persia, Baluchistan, Turkestan, Northern India, and Kashmir (Gilgit), and 
in the latter two regions it has been met with at altitudes of about 5000 feet above 
the sea. 
It lives on small rodents, the remains of which I have removed from its stomach. 
It frequents the surroundings of the Pyramids of Gizeh, where it is not unfrequently 
found in the open deep tombs, and is also prevalent along the margin of the delta, and 
in the delta itself wherever there is dry sandy ground and sparse vegetation. 
According to Dr. W. Innes it is known to the natives as ^j \ \=ar'am dhmar ; 
I have also heard it called arkam, which is doubtless the same as the aerkam of 
Forsk&l, J | meaning ashy. 
It is seen in the possession of snake-charmers from Calcutta to Cairo. 
AVith one exception, viz. Gilgit in Kashmir (5000 ft.), the ventrals of this species, 
over the wide area of its distribution, Algeria to the North-west Provinces of India, 
do not exceed 248 in number ; but in Gilgit they rise to 278, which is a very remarkable 
increase. In North-western Africa 219 to 248 ventrals are met with, but in only 4 of 
13 individuals from Egypt proper are there more than 227 such shields, the higher 
numbers being 233, 234, 242, and 244. In Eastern Arabia the ventrals fall as low 
as 211, but in Persia, and further to the east, with the exception of Gilgit, the variation 
of the ventrals is much the same as in North-western Africa. 
In tracing the species from west to east it will be observed that there is a distinct 
increase in the number of the subcaudals, the lowest number of these shields in 
Northern Africa being 68 and the highest 78, while from Persia to Rajputana 80 to 
110 occur. We have thus at the extreme west snakes with the following formula : 
V. 219, S.C. 68; and at the extreme east snakes with V. 278, S.C. 110— thus yielding 
the striking variation of V. 59, S.C. 42. 
