112 
MUSCICAPIKS. 
no doubt that the three aberrant families of the 
Dentirostres unite into a circle of their own, inde- 
pendent of their connexion to the shrikes ( Laniadce ) 
and the thrushes ( Merulidw ). 
With these preliminary observations on the lead- 
ing characters of this extensive assemblage of birds, 
we shall now proceed to the names and definitions 
of the genera composing it. These appear to be 
as follows: — 1. Ruipidura, the Fan-tailed Fly- 
catchers; 2. Monacha, the Oriole, or Hooded 
Fly-catchers ; and, 3. Megalophcs, or Great- 
crested Fly-catchers. These three appear to form 
the aberrant group, as representing the rasorial, 
the grallatorial, and the fissirostral types. The 
fourth genus is Todus, composed of the well 
known Todies, or South American Flycatchers. 
And the fifth is Muscicapa, consisting entirely of 
those, pre-eminently typical, which are restricted 
to the Old World. 
Our proposition is, that these genera form a cir- 
cular group. But before we enter into those details 
by which we hope to substantiate this assertion, let 
us, in the first instance, briefly state the prominent 
or typical distinctions of each, and then compare 
them, in our usual manner, with some other well 
known and authenticated groups, whose internal 
relations have stood the test of experience and rigid 
analysis. And, first, they may be compared with 
the Orders of Perchers in the following manner : — 
