78 VENOMS 



(f) Atheris. 



Head very distinct from neck, covered v^^ith imbricate scales ; 

 eyes large, with vertical pupils, usually separated from the labial 

 shields by small scales; nostrils lateral. Body slightly compressed ; 

 scales keeled, with apical pits. Tail moderate, prehenfiile ; sub- 

 caudal scales in a single row. 



(1) A. clilorcchis. — No supraciliary horn-like scales; 9 — 11 scales 

 from eye to eye ; 25 — 36 rows of scales in the middle of the body, 

 strongly keeled ; 154 — 165 ventrals ; 53 — (52 subcaudals. 



Colour green, uniform or with small yellow spots ; end of tail 

 yellowish or blackish. 



Total length, 520 millimetres ; tail 85. 



Habitat : West Africa, from Liberia to the Ogowai. 



(2) A. squamiger. — No supraciliary horn-like scales ; 7 — 8 scales 

 from eye to eye ; 15 — 25 rows of scales in the middle of the bod}^ 

 strongly keeled; 153 — 173 ventrals; 51 — 95 subcaudals. 



Colour olive, uniform or with more or less regular, narrow 

 yellow cross-bands, or yellow with green spots ; belly pale olive, 

 marbled with black or yellow, or uniform yellow. 



Total length, 550 millimetres ; tail 100. 



Habitat : West Africa, from the Cameroons to Angola. 



(3) A. ccratophoriis. — Several erect, supraciliary horn-like scales ; 

 9 — 10 scales from eye to eye ; 25 rows of scales in the middle of 

 the body, strongly keeled ; 142 ventrals ; 55 subcaudals. 



Colour dark olive, with black spots forming cross-bands ; belly 

 pale olive, speckled with black. 



Total length, 210 millimetres ; tail 65. 

 Habitat: East Africa. 



(g) Atractaspis. 



(Fig. 4-J.) 



This genus is characterised by enormous poison-fangs, a few 

 teeth on the palatines, and none on the pterygoids. The mandible, 

 which is edentulous in front, has only two or three small teeth in 



