KXTEBNAL anatomy. PEEPECT AND EVEN TAILS. ,99 
moderate tail is about equal to the length of the body ; 
and all above this are termed long tails. 
(89.) A perfect tail, in the great majority of birds 
consists of twelve feathers; but in the Rasorial order, and 
even in some of its representatives, this number amounts 
to eighteen, while in a very few birds, as in the Brazilian 
anoo, there are only ei,ght. The root or base of these 
feathers are protected by others, generaUy shorter, both 
above and below : these are termed the upper and the 
under tail covers. Generally speaking, those birds 
which have the broadest tails, have the longest tail 
covers, as we see in the jieacocks. Yet it is somewhat 
singular, that in the typical Grallatorial birds, both 
the upper and under covers are nearly, if not quite as 
long as the tail itself, so that it is really often difficult 
to separate and discriminate the two. Many of the 
cuckows (which represent the Grallatores in the tribe 
pi ScanauTeii) exhibit the same prohmgation, though 
tn a less degree, of tbe upper covers, while those of 
the Cehlepgrbue, or caterjiillar catchers, are remarkably 
stiff. We may now pass on to tbe different forms of 
tails, which we shall term, — 1. even; 2. rounded; 3. fan. 
shaped ; 4. graduated ; 5. cuneated ; 6. arcuated • 
7. spatulate ; 8. slender; 9. forked ; 10. lyre-shaped; 
11. boat-shaped ; 12. compressed ; 13. plumed- 14’ 
scansorial. ’ 
(90.) 1. An ewji tail implies, that the feathers, when 
not expanded, are all of the same length. This struc. 
ture is not so common as might be at first supposed' 
tor there are comparatively very few birds in which the 
exterior or outermost feather on each side of the tail 
|s not slightly shorter than those in the middle. It also 
lajqiens, that in specimens set up by unskilful bird- 
stutters, a tail, naturally even, is so much expanded that 
ts form appears to lx- rounded. The French seem to 
have introduced tbe word “even tail,” into their lan- 
guage from ours, but have apjilied it, most erroneously, to 
such tails only as are fan shaped. 2. Rounded tails are 
the most prevalent; the term being given to such as have 
H 2 
