SIGMODUS TRICOLOR. 407 
gaze intently on the ground, and, if any prey be in sight, pounce 
upon it with great celerity, their companions, whilst the successful 
foragers are devouring their booty, continuing to move on slowly as 
before.” 
Head light pearl-grey; cheeks white, margined behind by a 
black crescent; neck and under parts pure white; back and 
wines glossy, greenish-black, with a white strip along the latter; 
two outer tail-feathers pure white; all the tail-feathers broadly 
tipped with white; bill black; legs pale yellow. Length, 8’’; 
wing, 43’’; tail, 3’” 10°”. 
Fig. Smith, Ill. Zool. 8. Afr. pl. 5. 
390. Sramopus ar WAN: Z Retzius’ He'met Shrike. 
This species is easily recognized from the other South African 
Helmet Shrikes by the colouration of its back, which is ashy brown, 
contrasting with the head, which is black, as well as the frontal 
erest and hind neck. The whole under surface is black. It only 
occurs in the very northern parts of the South African sub-region. 
Mr. Andersson writes :—‘‘ When encamped in the desert, a few 
days’ journey south of the Okavango, I for the first and only time 
observed this fine Shrike. The flock consisted of six individuals, an 
adult male and female and four young birds of both sexes, all of 
which I secured after much running and dodging, as they were 
exceedingly wary and watchful, always perching on the loftiest and 
most exposed trees, in which respect they differed from the preced- 
ing species, though they resembled it in the manner in which they 
were feeding when I first saw them.” Senor Anchieta has met with 
ee ee ee 
the species at Caconda, Maconjo, and Humbe; it was very abundant 
in the latter locality, and was called by the natives Kanjuele and 
Banvo. 
391. Siamopus TRIcoLor, Gray. Kirk’s Helmet Shrike. 
This species replaces the foregoing one in the Zambesi, where it 
was discovered by Dr. Kirk during the Livingstone expedition. It 
. tay be briefly described as resembling S. retzii, but is smaller, with 
| the wing 5 instead of 5°25 inches, and differs by having the back 
drab brown. 
Adult.—General colour above black, with a slight greenish gloss, 
the quills and tail uniform with the back, all the primaries with a 
