The members of this subfamily consist of three genera of birds with an extraordinary superficial resemblance to Wagtails, i. e., they are black and white birds with long tails, which they are always wagging, and they run along in front of one in waterways and forest-paths. Structurally they are very different, having ten primaries well developed and a much stronger bill.
They differ from the members of the Phaenicurinae, with which Oates placed them, in the unusual shape of the tail, which is very deeply forked, yet has the outermost feathers shorter than the next pair.
The sexes are alike and the young go through two colour-phases before they assume the adult plumage.
The bill is strong and fairly stout, the lower mandible being bulged in the middle; the rictal bristles are well developed, the wing is long and the first primary is about half the length of the second.
Key to Genera.
A. Tail much longer than wing; middle rec-
trices one-third the length of longest Enicurus, p. 56.
B. Tail about equal to wing; middle rectrices
about half the length of tail Hydrocichla, p. C3.
C. Tail shorter than wing; middle rectrices
reaching nearly to end of tail Microcichla, p. 65.