PASSERES. MOTACILLA. 207 
bordered with white. Legs and toes deep yellowish- 
brown ; strong. 
The female is similar in plumage to the male bird. 
Genus XXXI. WAGTAIL. MOTACILLA, Lath. 
GENERIC CHARACTERS. 
Bill slender, strait, subulated, carinated, emarginated, and 
describing an angle upon the forehead. Tomia of both 
mandibles slightly compressed inwards, about the middle of 
the bill. Forehead low and depressed. Nostrils basal, la- 
teral, oval, and partly concealed by a naked membrane. 
Tarsus considerably. longer than the middle toe. ‘Toes three 
before and one behind ; the outer being joined at its base to 
the middle one. Hind claw strong, and sometimes of consi- 
derable length. Wings having the first quill very short ; the 
second the longest in the wing; and one of the greater co- 
-verts being as long as the quills. Tail very long, and gene- 
rally square at the end. 
The members of this well-marked genus are very active 
birds; and haunt the banks of rivulets, the pebbled margins 
of rivers, and extensive meadows in the neighbourhood of 
water. Their progressive motion is by running. They feed 
on insects, taken both on the ground, and on wing; also on 
worms and larve. ‘They are subject to a double (that is, 
autumnal and vernal) moult; the latter of which changes the 
colour of the neck, and, in some species, the head of the bird. 
They are confined to the Old Continent. 
The lengthened tail of this genus is kept in continual mo- 
tion perpendicularly, accompanied by a lateral (or horizontal) 
expansion of the feathers. 
