that connect the Orders and Families of Birds. 461 
though with gigantic dimensions, the exact bill of the Ani. The 
series of affinity, in which the Scansores are united, thus returns 
into itself. 
| $ 5. TENUIROSTRES. 
The genus Certhia, as originally instituted by Linnzus, con- 
tained, besides the true Certhia and its congeners, which form 
the extreme family of the preceding tribe, all those birds whose 
slender and gradually curved bills, and delicate formation of 
body, added to their practice of employing their tongues in: 
taking their food, indicated a strong affinity to each other, and 
which have since been particularized by authors under the va- 
rious names of Nectarinia, Cinnyris, Drepanis, &c. To the 
group thus known and described by the Swedish naturalist, 
later ornithologists, who have strictly followed his steps, have 
added another, discovered since his time in Australasia, similar 
in habits and manners, and now distinguished by the generic 
title of Meliphaga. The whole of the birds, however, thus united 
by close affinities, and as such generally brought together by 
systematic writers into one conterminous series, are decidedly 
divisible into two distinct groups, naturally arranging them- 
selves under different subdivisions of the order. The family of 
Certhiade, as we have seen above, live upon animal food ; while 
the remaining genera of the Linnean Certhia subsist chiefly upon 
vegetable juices. "The tongues of each, though similar in being 
more or less extensible, and in being the medium through which 
they are supplied with food, are equally distinct as the nature of 
the food itself. Those of the former are sharp, and of a spear- 
like form, as if to transfix the insects which are their prey ; while 
those of the latter are divided into tubular filaments, which ap- 
pear exclusively adapted to the purposes of suction. In other 
particulars they exhibit an equal difference. The Certhiade 
climb, and their feet are of a conformable structure : but the feet 
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