250 A JOURNEY UP THE RIVER CONGO. 
-grebe’s, each toe being lined with a membrane a quarter of 
an inch in width. The general appearance of the bird 
recalls at once the darters, the herons, the ducks, and the 
grebes. When swimming, it lies somewhat low in the 
water, and the neck, which is rather long and “kinked,” 
moves slowly backwards and forwards, as if poising the 
head to dart at a fish. On the river Chiluango, where I 
have seen it Swimming among the mangrove stalks, little 
more than the neck was visible as it swain, and my com- 
panions in the boat took it at first for a snake raising its 
head from the water. The “darter” (Plotus Levaillantv) 
is one of the commonest birds .on the Congo. It affects 
every piece of water, either forming cataracts, tranquil 
pools or stagnant marshes. A small cormorant is also 
frequently seen, but is not so universally abundant as the 
darter. About the Congo region, whether on the Upper 
river, the estuary, or the neighbouring coast, types of all 
the genera of the sub-order Pelicant may be met with. 
The frigate-bird (Fregata aqwila) is not uncommonly seen 
off Banana Point, and the tropic-bird (Phethon ewthereus) is 
of even more frequent occurrence. As this latter breeds 
on the island of Sao Thome, he is not so far from home, 
off the Congo mouth. Then there is a gannet, Sula 
capensis, which occasionally visits the estuary of the~ 
Congo in myriads; and, finally, the darters and cormorants 
are also represented on the river, together with the pelican. 
This giant member of the family is very partial in his 
distribution ; sometimes you find him in great quantities, 
as on Stanley Pool, and about the broadened stream at 
Bolobo, at other times he will be absent or unheard of over 
a hundred miles of river. On an unapproachable island 
above the Falls of Yelala, a colony of pelicans, apparently 
Pelicanus onocrotalus, has established itself, and made the 
island—which, owing to the rapids, one could only reach 
by balloon—a great breeding-place, the shores of which 
are white with guano. While I was stopping at the Baptist 
Mission at Angu Angu, and afterwards at Vivi, two places 
nearly opposite to one another, a strange mortality seemed 
to exist among the young pelicans, birds of one year old, 
