76 VENOMS 



two small shields, separated from their neighbours by 5 — (> series 

 of scales ; 10 — 12 supralabials ; 8 mfralabials. Scales on the bodk- 

 in 23 — 27 rows ; 102 — 122 ventrals, rather strongl}'' keeled at the 

 sides ; 18 — 26 subcaudals. Colour dull yellow, pale brown or red- 

 dish, with or without black spots ; end of tail often black above ; 

 ventral surface white. 



Total length, 310 millimetres ; tail 30. 



Habitat: Northern border of the Sahara, from Algeria to Egypt. 



The snakes belonging to this genus live constantly hidden in the 

 sand, lying in wait for small birds, which alight beside them with- 

 out suspicion, mistaking their horns for insects or larva^ ; they also 

 feed upon mice. Their poison-fangs are of relatively large size. 



These small and exceedingly active vipers, whose colour har- 

 monises marvellously with their surroundings, are very dangerous 

 to the Arabs and blacks, who walk barefooted ; they frequently 

 cause fatal accidents. 



They are able to exist for a very long time without drinking. 

 They are attracted by the fires which are lighted at night round 

 caravan encampments. 



(e) Echis. 



(See Asia, p. 48.) 



(1) E. carinatus (Efa, Viper of the Pyramids). — The same as 

 met with in Persia, Arabia, and India. Very common in the 

 environs of Cairo, and throughout Egypt and Abyssinia. It often 

 makes its way into towns and villages. Brehm records that he 

 more than once found an Efa in his house at Khartoum, and that 

 on one occasion he discovered one of these vipers coiled up beneath 

 the covering of his bed. At another time, getting up in the night, 

 he put his foot on one of these animals and was not bitten, the 

 reptile being very fortunately just at that moment in the act of 

 devouring a tame bird which it had seized. 



It hardly ever happens that a native of Egypt can bring 



