Expedition to the Zambesi Biver. 85 
(measured in flesh) 6 55 inches, wing 3*1. Iris hazel; bill 
black; legs and feet flesh-colour. 
103. Cichladusa arcuata (Peters). 
Near Senna, in bush-grown country. 
Adult ? . Iris straw-colour; bill black; legs and feet slate- 
colour. This bird must be uncommon, since we never met 
with it again after leaving Senna. 
104. Cossypha natalensis (Smith). 
Where the preceding species is present C. natalensis 
appears to be absent. 
This bird is decidedly rare along the Zambesi. Our 
single specimen w^*obtained close to the mouth of the 
Kafue river, in Decfenrber, its sexual organs being in a 
breeding condition. 
The mantle is largely washed with orange, and the wing- 
coverts are a bright bluish grey. 
Total length (measured in flesh) 6*7 inches, wing 3*45. 
Legs and feet brown. 
105. Cossypha heuglini (Hartl.). 
The scarcity of singing-birds in the Zambesi woods is 
remarkable. There is, however, a noteworthy exception, 
that of this beautiful red Ground-Thrush, the song of which 
seems to gain in intensity from the surrounding silence. In 
the Zambesi region this species commences to breed towards 
the end of December, the month when the first fall of rain 
is generally experienced. The male bird is then in full 
song, but at other times of the year the singing is reduced 
to a short string of babbling notes. The song is rich and 
mellow, the long-drawn opening notes increasing in volume, 
suddenly to break off into a string of bubbling sounds that 
turn the next moment to soft volubility, the voice being 
raised in pitch till it becomes like a faint whisper, just as if 
the singer was soliloquizing. 
This Cossypha frequents thick* undergrowth, waste land 
where there are bush-grown dells holding water or reed-beds 
bordering the river. It is a shy bird and keeps much to the 
bottom of the tangled brushwood, decoying the listener on 
