Annals of the Transvaal Museum. 
115 
•“ schwarze momba.” Our specimen is black in colour. Length, 1280 mm. 
of which the tail occupies 245 mm. : 225 ventrals, caudal s in 70 rows. 
This black form we have never seen previously in South x\frica but it 
may be noted that according to Smith a black variety of Naia hair occurs 
in the subcontinent. 
Family VIPERIDAF. 
Genus Bitis, Gray. 
Bouleng., B. M. Cat. Ill, p. 492. 
B. caudalis, Smith. 
Viper a caudalis, Smith, 111. Ptept. PI. vii. 
B. caudalis, Bouleng., 1. c. p. 498 : Werner, Kept. Amph. Schultzes Reise, 1910, p. 367. 
33 specimens, of which 12 are embryos taken from a single specimen, 
from the Great Karas Mountains and district. Localities : 2012, a large 
female from Wasserfall ; 2013-2015, 2032, also from Wasserfall ; 2016- 
2019, Narudas Slid ; 2020-2022, Kraikluft (5000 to 5200 feet) ; 2023-2027, 
Sandmund ; 2028, Groendoorn ; 2029, between Groendoorn and Nakeis ; 
2030, 2031, Nakeis (Klein Karas). 
All our specimens are typical caudalis , but in a few cases there may 
be a small auxiliary horn -like scale at the side of the large pointed scute 
above the eye. It would seem that this horn may be formed by the 
coalescence of two enlarged scales. In the very young and in embryos 
the horn is very ill-developed, and may be indicated by nothing more 
than a iprominence above the eye, the scale which is later to form the 
horn being only slightly larger and longer than the adjacent scales. 
The median subcaudals near the vent are smooth or feebly keeled. 
The development of the keel in our series cannot be correlated with age, 
the embryos possessing about the same degree of keeling to the subcaudals 
as the largest individuals. 
The colouring is variable. Some of our specimens are chestnut- 
brown ; others are a dark grey-brown ; one specimen from Narudas Slid 
is very beautifully marked with dark brown edged with light yellow, 
umber, and slate-blue, these markings being continued on to the head in 
a very distinctive way. The largest example measures 473 mm. in total 
length, of which the tail is 43 mm. : ventrals 153, caudals in 31 rows : 
25 scales round the middle of the body. 
It may be added that no specimen of B. cornuta was seen on this 
expedition. 
