o 58 ON THE CLASSIFICATION OF BIRDS. 
pected of having a suctorial tongue, however strongly it 
may be allied, in all other parts of its organisation, with 
croups far differently situated. When, therefore, it is 
.^id tliat the five tribes above mentioned have been 
universally admitted, it is necessary to premise that no 
two writers have yet agreed on their definite nature. 
Hence it becomes advisable, before proceeding further, 
to state our views of their prominent or typical dis- 
tinctions, , . r ' 
(274.) The pbimarV chicles of the order before us 
appear to be three. The first composed of those fami- 
lies wliere the bill is very conspicuously notched, and 
the food almost exclusively derived from insects ; these 
are the Dentirostbes. The second includes such as 
have the notch much slighter, and who feed almost indis- 
criminately both upon animal and vegetable substances ; 
these are the Conirostrks, the bill being more conic 
than the latter: hut in both tribes the feet are the 
same ; that is, the tarsus is not uniformly short, and 
there are three toes before and one behind. The third 
circle is composed of theCuRTiPEDEs; differing materi- 
ally from the two former in having the tarsus much 
shorter, the notch of the bill either obsolete or altogether 
wanting, and the position of the toes variable. Under 
this last group, which is the aberrant division, we 
include the three tribes of Sauuiores, Temiirostres, 
and Fissiroxtreji. Preliminary remarks will be given 
upon each of the foregoing tribc-s as they come succes- 
sively under our elucidation ; but, that the student may 
have a general idea of their nature, we shall here de- 
signate their chief peculiarities, and the different fami- 
lies of birds they respectively contain. 
fSTfi.) The Dentirostbes, as the name implies, is 
distinguished by a distinctly notched bill, and by being 
the greatest destroyers of insects among the perchers : 
wdth very few exceptions, they either live entirely upon 
insects, or only resort to fruit wlien deprived of their 
favourite nourishment. In accordance with these habits, 
the mouth, or rictus, is defended on each side by bristles. 
