284 THE EEPTILES OF EGYPT. 
posteriorly, and separated from each other by narrow pale interspaces or lines ; upper 
labials sometimes slightly orange-yellow with dark margins ; underparts pure white. 
The largest adult male from Egypt is 1105 millim. long, of which the tail forms 
170 millim. 
It is distributed over the Nile valley from near the Mediterranean to Sennaar, and 
is also present in Somaliland and Eritrea. 
This species is generally found on the margin of the desert. It frequents houses. 
I removed an entire Motacilla alba, Linn., from the stomach of one of these snakes. 
In Egypt it is called ^ ^| = abu uyun=t\ie father of eyes; and it was once 
known in scientific literature as " Telescopus," owing to the prominence of its eyes. 
Forskal in his journey through El Yemen, the most southern province of Arabia on 
the littoral of the Red Sea, obtained a snake he described as C. dhara, which undoubtedly 
belongs to this genus. Unfortunately he gave no information regarding the condition 
of its anal, nor did he mention the number of scales round its body. Reuss, in 1834, 
described the present species, which is evidently closely allied to C. dhara, Forskal, 
from a specimen obtained in Egypt by Ruppell. I have examined the type in the 
Frankfort Museum. It has 268 ventrals, a divided anal, 74 subcaudals, and 23 rows 
of scales round its body. In 1895, I described from Eastern Arabia another species, 
T. guentheri, characterized by 21 (or 19, E. Africa) rows of scales across the body, 
205-274 ventrals, an undivided anal, and 69-75 subcaudals, or 110 (Usambara). Since 
then I have received from Medina a specimen with all the characters of Tarbophis 
obtusus, i. e. 23 rows of scales and a divided anal. As the two species are thus present 
in Arabia, it is impossible to say which corresponds to C. dhara, Forsk&l. It is worthy 
of note that the snake in the Stuttgart Museum figured by Jan l as Telescopus obtusus 
has an undivided anal and came from Egypt. Snakes corresponding to those from 
Eastern Arabia (i. e. T. guentheri) are found at Jerusalem 2 , and at Ngatana, E. Africa 3 . 
In the following table I have registered a few details in the arrangement of the head- 
shields of all the species of the genus, the number of the ventrals and subcaudals, the 
character of their anals, and the number of scales round their bodies. It will be seen 
wherein T. obtusus and T. guentheri differ from one another. 
If the specimen from Somaliland with only 213 ventrals has been correctly deter- 
mined, the variation in the number of the ventrals is very great, as one Egyptian snake 
has as many as 272 shields. The same remark is also even more called for in the case 
of T. guentheri, as a representative of that species at Ngatana, British East Africa, has 
only 205 ventrals, whereas at Maskat, in Arabia, the ventrals rise to 274, thus giving a 
variation of 69 shields. It would seem that its north-eastward range, from Ngatana 
to Maskat, is characterized by a gradual increase in the number of the ventrals. 
1 Icon. Gen. livr. 38, 1871, pi. i. fig. 4. 
: Werner, Verb, zool.-bor. Ges. Wien, 1896, xlvi. p. 301. 
3 Blgr. Cat. Snakes B. M. iii. 1896, p. 52. 
