DIVISION OPISTHOGLYPHA. 125 



6. PsAMMOPHis siBiLANs. Hissing Sand Snake ; Blaas Zand Slang. 



Synonyms — Coluber sibilans ; Psammophis thomasi. 

 Colour — Colour very variable. 



A. Olive or brown above, the scales mostly black-edged ; 

 a more or less distinct narrow yellow vertebral line and a broader 

 yellow streak along each side of the back ; head with yellow, 

 black-edged longitudinal streaks in front, and transverse ones 

 behind, which markings, however, may become very indistinct 

 in the adult ; upper lip yellowish white, uniform or with a few 

 brown or black dots on the anterior shields ; lower parts including 

 the lower half of outer row of scales yellowish white, uniform or 

 with a faint brown lateral line. 



B. As in A, but no trace of a light vertebral line. 



C. Uniform brown or greyish-olive above, the markings on 

 the head very indistinct ; upper lip and lower parts, including 

 lower third of outer row of scales, uniform yellowish white. 



D. Brown or ohve above, with lateral streaks and head 

 markings as in A. Vertebral line absent or reduced to a series 

 of yellow dots, one on each scale ; upper lip with brown or 

 black dots ; lower parts including lower half of outer row of 

 scales, white, with a continuous or interrupted black longitudinal 

 line on each side of the belly. 



E. Uniform brown or ohve above, with more or less distinct traces 

 of the markings on the head ; upper lip yellowish, with brown 

 or blackish dots ; lower parts including lower third or lower 

 half of outer row of scales, yellowish, with a brown or black 

 line on each side of the belly. 



F. Olive above, which colour extends down to the ends of 

 the ventrals, uniform or dotted with blackish, or with most of 

 the scales black-edged ; sometimes in the young with traces of 

 hght longitudinal stripes ; upper lip yellowish, spotted or speckled 

 with black ; belly yellowish or pale olive, uniform or dotted 

 with black on the sides, the dots sometimes confluent into longi- 

 tudinal lines. 



Average length — 4 feet. Some specimens attain a length of over 



5 feet. 

 Distribution — Both provinces of Cape Colony ; Natal ; Zululand ; 



Transvaal ; Southern Rhodesia ; North through Tropical Africa 



to Egypt. 



7. Psammophis brevriostris. Short-snouted Sand Snake ; Kort-snoet 



Zand Slang. 



Synonym — Psammophis sibilans. 



Colour — Brown or dark olive on the back (7 rows of scales), pale olive 

 on the sides down to the ventrals, the two shades separated by 

 a more or less distinct lighter streak ; a yellowish black-edged 

 spot usually present on each vertebral scale ; head uniform 

 olive brown in the adult, in the young with a yellowish streak 

 along the frontal, and yellowish cross-bars behind ; yellowish 

 white beneath, with a series of olive or blackish dots or short 

 streaks along each side. 



Average length — 4 feet. Some specimens attain a length of over 

 5 feet. 



Distribution — Both provinces of Cape Colony ; Natal ; Zululand ; 

 Transvaal ; Angola. 



8. Psammophis jall.e. Sand Snake. 

 Distribution — Southern Rhodesia. 



