112 ON THK CLASSIFICATION OP BIRDS. 
in Picus and Certhia familiaris ; 4. linear (e), where the 
form of the feather is narrow, of equal breadth, and the 
tip obtuse or truncate, as in Tamatia ; 5. mucronate, 
when the end is broad and nearly truncate; but the tip 
of the shaft slightly projects, so as to form a flexible 
thorn-like point, as in the common jay, and in 
Ptilonorhynehun (g), and Phonigama {h); (). cuspidate, 
when this point is more lengthened and slightly rigid, 
as in Synallaxis (i) ; 7* acuminate, when the point 
is naked, rigid, and sharp, as in Dendrocolaptes (k) and 
Cheetura (i) ; 8. emargiuate, having a notch in the 
middle of the tip, as in Merops (m) ; Q. filiform, when 
the feathers end in long wire-like processes ; 1 0. capitate 
(ii), when the end of a linear feather is rather dilated ; 1 1 . 
spatulnte (o),when the shaft is naked towards the middle, 
but suddenly webbed at its extremity, as in the racket- 
tailed humming-birds, &c. ; 1 2. divaricated ( p), when 
the webs form a point on each side, as if the shaft was 
broken, as in Temnnrus maeulatus ; 18. worn (q), 
formed like the last, but accidentally the shaft and webs, 
as in the woodpeckers, being worn by friction. 
( 1 04.) I'he FOOT of a bird is nearly of as much import- 
ance to its existence as its wings ; although it may be 
supposed that many sorts, the swallow, for instance, would 
be able to sustain life for a much longer period under 
the injury of a foot, than it would do if an equally se- 
vere accident had happened to the wing. The leg is obvi- 
ously divided into three parts; 1. the thigh; 2. the shank, 
or tarsus ; and 3. the foot itself, composed of the toes. 
The thigh is subject to very few variations beyond relative 
length, and in lieing more or less clothed with feathers. 
In aquatic birds it is generally naked before it reaches 
the knee joint. In the perching and rapacious orders, it 
is invariably clothed with feathers, more especially in the 
latter, where the feathers are more lengthened than usual, 
and often elegantly ornamented with spots and bands ; 
but when the lower part of the thigh is naked, it is 
covered with scales, nearly similar to those on the next 
joint: the tarsus and the foot, but chiefly the latter. 
