The only member of this genus is not greatly different from the
Motacillæ, but the tail is slightly shorter than the wing, being
intermediate in length between the tertials and primaries; the
claw of hind-toe is short as in Motacilla; under parts white with
a black band across the chest; upper parts with an olivaceous wash;
wing-feathers blackish brown; median and greater coverts tipped with
white, forming two conspicuous wing-bars; primaries and secondaries
with white spots on outer webs, forming two more bars. Of this genus
Oates says: "The structure of the tail in this genus is peculiar,
inasmuch as the middle pair of feathers is very markedly shorter than
the others and of a different color."