304 THE EEPTILES OF EGYPT. 
traversed transversely obliquely forwards by a few narrow yellowish lateral lines, 
becoming most distinct anteriorly and on the temporal region, where they mark off one 
or two large dark brown patches which have given rise to the term auritus applied to 
this species by Is. Geoffroy St.-Hilaire ; one of these yellow lines crosses the posterior 
portion of the parietals, and another lies behind the eye, involving the postoculars. The 
praeocular has a yellowish spot ; upper labials bright yellow or with orange and dark 
spots ; a yellow line traverses the canthus rostralis, at the anterior margin of which 
it sends an offshoot backwards along the sutures of the internasals and prefrontals to 
the frontal ; lower labials yellow or spotted with bright orange. This mesial 
yellow line into which the oblique lines pass is not unfrequently prolonged along 
the entire vertebral line of the snake to opposite the vent. The tail has the five 
principal bands usually well marked. The under surface from the chin backwards is 
generally rich yellow, frequently very light below the head and sometimes spotted 
with light orange ; but the angles of the ventrals may or may not have a dark line 
along them. 
In the uniformly coloured snakes the upper surface may be either dark brown or 
pale greyish brown, without bands of any kind beyond a faint indication occasionally 
of the yellow narrow vertebral line. The scales in these forms are more or less 
margined with black, and the head-markings become very obscure, and the dark line 
along the sides of the ventrals may be found in some, absent in others. In Egypt 
snakes presenting these different colour-variations are present in one and the same 
locality ; but the snake from Luxor is uniformly brownish above and yellow below, 
and the head-markings are indistinct, but in this respect it is resembled by snakes 
from Mahallet el Kebir in the delta and in Fayum. In the first of the last two 
localities snakes are met with of the striped character, the dark bands very strongly 
marked, and also the dark lateral line on the ventrals, but with the pale vertebral line, 
when present, represented only by an interrupted line of yellow spots, but generally 
one to each scale. Snakes presenting this form of coloration are found in the Nile 
valley as far south as Wadelai, at Kilimandjaro, and in tropical Africa as far west as 
Senegal. At Wadelai a type of coloration differing only in some details from the 
uniform type present at Mahallet el Kebir in the delta is also met with, and is also 
widely distributed over tropical Africa. It differs from the uniform type of coloration of 
the deltaic snakes, in which the first row of dorsal scales next the ventrals is yellowish, 
in having the lateral line of scales coloured like the rest of the upper surface, and 
in the ventrals, which are yellow in the Lower Egyptian snakes with a dark line, not 
unfrequently spotted with black, tending to form longitudinal lines. In the uniformly 
coloured deltaic snakes the lips are immaculate, whereas in the southern uniform type 
of coloration the upper lip is more or less spotted. The head-markings in both are 
indistinct. 
It attains to 1205 millim. in length, of which the tail forms 390 millim. 
