THAMNOPHILINE. 9 
-(10.) We now come tothe TuamnopHiLin2, or bush- 
shrikes, where we have the characteristics of the family 
much more distinctly developed than in either of the 
three preceding divisions. The habits of these birds 
are strikingly opposed to those of the aberrant divisions. 
They live among thick trees, bushes, and underwood, : 
where they are perpetually prowling about after insects 
and young and sickly birds ; while in the breeding season 
they are great destroyers of eggs. They neither seize 
their prey by the claws, nor do they dart at it by flight : 
and we thus find that the first are thick and rather 
blunt, and the wings so short as to indicate great fee- 
bleness of flight: the bill, being the instrument of capture, 
_ is always stout, much more lengthened than in the true 
shrikes, and very abruptly hooked at the end, which is 
armed with a strong tooth. These characters are va- 
riously modified in the five principal genera which we 
shall now enumerate. 
(11.) Of the genus Prionops only one species until 
lately was known (P. plumatus): it is common in Senegal, 
where it is stated to search for terrestrial insects in humid 
situations beneath the surface: this bird is remarkable for 
a peculiar kind of crest of rigid feathers, which not only 
falls back on the head, but is reversed over the base of 
the bill, giving a complete protection to the nostrils and 
the sides of the mouth. Now, we have already seen 
this very singular structure partially developed in the 
genus Tephrodornis; and there are so many other 
points of resemblance between the two, that we are in- 
clined to look upon this as the point of union between 
the bush and the forked-tailed shrikes, or the Tham- 
nophiline and the Dicrurine. 
(12.) The genus Thamnophilus next succeeds: it is 
strictly typical, and shows the perfection of that parti- 
cular structure which distinguishes the bush-shrikes : the 
- bill( fig.117.)is very powerful; and although many of the 
species far exceed the size of a thrush, there are others not 
much bigger than a wren. Itis also a strictly geographic 
group, being confined te the hotter latitudes of America, 
