Annals of the Transvaal Museum 
269 
stout, light brown in colour; the outermost primary is long, more than half 
the length of the second, and about one and a half times the length of th§ 
bill; tail about two-thirds of the length of the wing; colour dark slate or 
blackish above and yellow below, not subject to seasonal change and alike 
in the sexes, which are strictly monogamous. Its nest is composed of 
epiphytic creepers and in shape resembles that of Anaplectes. Its eggs are 
variable in colour. Its habitat is the dense forests of the eastern escarp- 
ment and the tropical low country where forests abound. 
Hyphanturgus Cab., type H. ocularius (A. Smith). This genus has much 
in common with the preceding in the shape of the nest, which is composed 
of strips of reed-blade and has a downwardly projecting entrance. From 
the preceding genera it may be distinguished by its much narrower bill, 
which is black; the tarsi and feet are slate blue and fairly stout; the outer- 
most primary is rather less than half the length of the second and about 
one and one-fourth the length of the culmen; the tail is about four-fifths 
of the length of the wing; there is no seasonal change of colour, but the 
males differ slightly in having more black on the head and throat. The eggs 
are pale greenish, sparingly marked with slate or slate and reddish, and the 
birds are most usually found in pairs. 
Sitagra Rchb., type 5. luteola Licht., constructs a nest very similar 
to the preceding, but lays immaculate white eggs. In its structural char- 
acters it differs in having a stouter bill; the tarsi and feet are also slate- 
blue and fairly stout ; the outermost primary is about a third of the length 
of the second and approximately the same length as the bill; the tail is 
about two-thirds of the length of the wing ; the males differ markedly from 
the females during the breeding season, the fore part of the head and throat 
being black and the underparts yellow. Sitagra cahanisi represents the 
genus in South Africa. 
We pass now to an assemblage of groups in which all of them have the 
legs and feet light brown; in most of them there is a seasonal change of 
colour, usually most marked in the males, and their nests do not contain 
a long, downwardly projecting, tubular entrance, though sometimes there 
is a slight addition to the entrance which points to the possibility of its 
being prevalent elsewhere. Until quite recently authors were content to 
place the black-headed ones in one genus and the rest in another; but this 
does not by any means show their relationship, and it was by doing this 
that we find Sitagra cahanisi placed side by side with “ Ploceus " or Hyphan- 
tornis velatus. The fact that cahanisi and velatus quite commonly build 
together in the same trees, but the nests and eggs can be more readily 
identified than the birds themselves (apart from the colour of the legs), 
seems to me to show that they are of distinct origin, their similarity being 
due simply to their subsisting upon the same food in the same environ- 
ment; it is an extraordinary case of convergence, and having regard to 
their being both polygamous* (at least they appear to us to be so) seems 
to be a good argument in favour of “genus splitting,” as we do not find 
them interbreeding. I am inclined to place them all under one genus, 
Hyphantornis, and for the present will do so until further evidence is 
adduced as to the advisability of making finer distinctions for subgeneric 
purposes and using the present ones for the genera. 
Hyphantornis G. R. Gray, type H. grandis Gray, is now commonly 
