182 
THE POISONOUS SNAKES OF THE ANGLO-EGYPTIAN SUDAN 
Piilt-AcUler 
that between the prae-frontals ; frontal a little longer than broad, much longer than its 
distance from the end of the snout, longer than the parietals, one pric- and one post-ocular ; 
teiniiorals small, 2 by 3 or 4 ; six uiiper labials, third and fourth entering the eye and 
largest ; first lower labial in contact with its fellow behind the symphysial; three lower 
laluals in contact with the chin-shields. Scales in 29-37 rows; ventrals 212-245 ; anal 
entire; suhcaudals 2(5-37, single. Uniform dark brown. 
“ Total length, 540 mm. ; tail, 45 mm. 
“ East and Central Africa.” 
The specimen collected by Dr. C. M. Wenyon at Nasser (Sobat Eiver) is somewhat 
longer (570 mm., tail 40 mm.) and really black. No other specimen is known from 
the Sudan. 
Two species of Atracfdxjiiti from Wadelai have been sent to the British Museum by 
Emin Pasha. As they may be found also in the Sudan, I give here the distinctive 
characters : — 
I. Anal divided ; suhcaudals all or greater part divided. (Scales in 25-27 rows ; 
ventrals 200-257) ... ^1. irreiiiiUtris, Reinhardt. 
II. Anal entire; suljcaudals, all or greater part entire. 
(1) I’ostocular in contact with a large temporal; third lower labial very 
large; scales in 19-21 rows; ventrals, 251-300 . uterriiiKi, 
Cimther. 
(2) Temiiorals small, 2 by 3 or 4 ; fourth or fifth lower labial largest; scales 
in 29-37 rows; ventrals, 212-245 ... A. micrulepidufa, Gunther. 
Genus : Bitis, Gray 
Head very distinct from neck, covered with small imbricate scales ; eye moderate or 
very small, with vertical pupil, separated from the labials by small scales; nostrils 
directed upwards or upwards and outwards, pierced in a single or divided nasal, with a 
deep pit or pocket above, closed by a valvular, crescentic supra-nasal. Scales keeled, in 
22-41 rows ; ventrals rounded ; tail very short; suhcaudals in two rows. 
Africa, South Arabia. 
Itilis arietans, Merrem 
Plate XVI IP, fig. 1 
Eoulenger, ('at. Snakes, IIP, 1890, p. 494; Werner, l.c., p. 1885. (Figured in 
Schlegel, ” Essai Physiognom. Serp.,” IP, Plate XXP, figs. 1-3 [1837]; Dumeril and 
liibron, “ Erpctologie Geuerale,” YIP, Plate PXXIX., fig. 1 [1854]; Jan, “ Iconogr. Gen. 
Gphid.,” 45, Plate VP, figs. 3, 4 [1874|.) 
“Puff-Adder” of the Dutch Colonists of South Africa. Nostrils directed upwuirds. 
No horns on the snout or above the eyes; one or two series of scales between the rostral 
and the nasal; scales in 29-41 rows, strongly keeled; outer row smooth or feebly 
keeled ; ventrals, 131-145 ; suhcaudals, 16-34 pairs. 
Yellowish, pale brown or orange above, marked with regular chevron-shaped dark 
hrown or black bars pointing backwards, or black with yellow or orange markings; a large 
dark blotch covering the crowm separated by a smaller inter-orbital blotch by a transverse 
yellow' line ; an oblique dark band below' and another behind the eye; yellowish-white 
below', uniform or with small dark spots. 
This very thick and bulky viper is the largest species of viper in the Sudan ; the longest 
specimen in the British Museum is 1350 mm. (tail ICO mm.), but no douljt it grow's still 
larger. It is known in the greater part of xlfrica, viz. from Southern Morocco, Kordofan and 
