62 VENOMS 



(3) N. melatioleuca. — Coloration very variable. Sides of the 

 head yellow or whitish ; labial shields tinged with black on the 

 posterior edge. 



Total length, 2,400 millimetres ; tail 400. 

 Habitat : Tropical Africa. 



(4) N. nigricollis. — Third supralabial shield the deepest, sixth 

 and seventh not in contact with the postoculars ; 183 — 228 ventral 

 scales ; 55 — 68 subcaudals. 



Coloration very variable ; lower surface of the neck with a black 

 transverse bar. 



Total length, 2,000 millimetres ; tail 300. 



Habitat : From Senegambia and Upper Egypt to Angola and 

 the Transvaal. 



(5) N. ayichietce. — Scales in 17 rows on the neck and on the 

 body ; 181 — 192 ventrals ; 52 — 62 subcaudals. 



Colour blackish or brown above ; end of snout and cheeks 

 yellow ; belly yellow or pale brown, with or without black cross-bar 

 under the neck. 



Total length, 1,800 millimetres ; tail 340. 



Habitat : Angola and Ovamboland. 



(6) N. goldii. — Eyes large, two-thirds the length of the snout 

 in adults. Scales in 15 rows on the neck and on the body ; 

 194 — 195 ventrals ; 88 subcaudals. 



Colour black, uniform, or with transverse series of small whitish 

 spots ; cheeks and end of snout white, with a black border at the 

 margin of the shields ; belly white in front, black behind ; sub- 

 caudal scales black. 



Total length, 1,750 millimetres. 



Habitat : Lower Niger. 



(d) Sepedon. 



Maxillary bones projecting considerably beyond the palatines, 

 with a pair of large poison-fangs ; no other maxillary teeth. Head 

 not distinct from neck ; eyes of moderate size, with round pupils ; 



