62 VENOMS 
(3) N. melanoleuca.—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. anchiete.—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.—Kyes 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; 
