PSAMMOPHIS SCHOKAEI. 297 
surface the same as in the striped forms. In others, the spots of the dorsal lines 
become nearly obsolete ; also every alternate scale along the mesial line of the back 
becomes paler than the surrounding scales, so that a vertebral chain of paler scales is 
present. In such forms the black innermost spots on the ventrals become fine 
longitudinal lines enclosing a broad dusky ashy space, prolonged to near the extremity 
of the tail, finely punctulated with minute blackish spots. The head-markings remain 
intact. 
In others the general colour may be pale greyish olive above without black spots 
feebly indicated, but with a tendency to form a pale dorsal streak here and there. 
In these forms the head-markings are practically obsolete, but a short narrow dark 
band is present behind the eye. Under surface of head immaculate. The spots on 
the angles of the ventrals very feebly marked, also the dark lines, but a broad yellowish 
band, more or less speckled at its margins, occupies the centre of the ventrals and is 
continued to the vent, the centre of the first few ventrals with a dark spot. In these 
uniformly coloured forms the scales are generally finely dotted with black, and snakes 
of this type of coloration are common in Lower Egypt. Some examples of this species 
(Island of Shadwan, Assuan, Oasis of Khargeh, and Khartum) are more or less rosy 
red or reddish brown, without any trace of markings except the line from the nostril to 
the eye and on the temporal region, and a few spots, all of which become pronounced 
reddish rosy. The ventrals become bright rosy red and the broad mesial band almost 
orange-red. 
The figures I have given of this species illustrate the extremes of colour-variation. 
On Plate XLI. there is a representation of the striped form, and in the background a 
figure of the uniformly greyish-coloured snake finely dotted with blackish, while in 
Plate XLII. the uniformly rufous variety from the Oasis of Khargeh is depicted. 
The striped variety with its modifications is especially well represented in the Suakin- 
Durrur district, where I have never observed snakes exactly corresponding to the greyish 
or yellowish-olive black-dotted form found in Lower Egypt, and also in Arabia, Persia, 
and Sind. 
The largest male has a total length of 1480 millim., of which the tail constitutes 
335 millim. 
This species is widely distributed over Northern Africa. It has been recorded from 
the south as far as Sennaar, and from Eritrea to the east. It is present in Syria, 
Arabia, and extends from Persia as far east as Sind. 
It is found in dry and semi-desert areas, and I have never met with it on the moist 
alluvial soil of the fields. In Lower Egypt it was generally found under stones on 
the margin of the desert, but on the plain of Suakin at the roots of bushes. 
Its Arabic name is ;J -wl I ^\=abu el suyur =the father of stripes. The natives do 
not distinguish it from the next species, P. sibilans. 
