FISCUS 241 
three groups. In two of these the black of the hinder half of the head 
extends down the whole length of the neck; this includes the typical group 
of F. collaris and its allies with a more graduated tail and no broad white 
basal band to it and with the crown and entire hinder half of neck blackish. 
The group to which F’. cabanis: and F’. excubitorius belong is characterized 
by the long but less graduated tail which has a broad basal band of white. 
The third group, comprising only Ff’. mackinnoni, has the entire crown and 
hinder half of the neck grey like the back and in this respect closely resembles 
the Shrikes which I have placed in the genus Lanius, but is distinguished 
from them not only by the rufous patch on the flanks of the females but 
also by there being no white bases to any of the quills. 
KEY TO THE SPECIES. 
a. Base of centre tail-feathers black; wing not more than 
4 inches. 
at, Upper tail-coverts of the same colour as the back, 
hinder half of neck and the crown. 
a?, Back grey, quills entirely black . . . mackinnont. 
b2, Back black, or dusky brown in the eee of 
FF. nubicus. 
a’. A broad whitish forehead, and base of both webs 
of primaries white .. . nubicus. 
6%, Hntire forehead and outer ae of Smee ca 
black gas newton. 
bt, . Rump and upper tail- pera oe ; crown ed imcee 
half of neck black or nearly so. 
c?, Upper back of the same shade of black as the crown. 
c, Less white on the tail; greater portion of outer 
pair of tail-feathers black. 
a*. Awhiteeyebrow . . ee OmwTiat. 
b+, No white on upper half of end ne snuthi. 
d’. More white on the tail, greater portion of outer 
pair of tail-feathers white. 
c*. Throat and breast tinged with grey . . collaris. 
d*, Throat and breast white not tinged with BEE 
a®, With no white on the upper half of the head. huwmeralis. 
b5. Front of forehead and the eyebrows white . swbcoronatus. 
d*. Upper back grey. 
e8, Secondaries with broad white ends, outer pair of 
tail-feathers with not more than their shafts black somalicus. 
f8, Secondaries entirely black; outer tail-feathers 
with a large portion of their inner webs black . dorsalis. 
