MOTACILLA. 193 
and the Goldcrests. It is impossible to guess what species was considered 
typical by Linnzeus ; but subsequent writers in subdividing the genus have 
restricted it to the Wagtails, the White Wagtail being accepted as the 
type because it is the Ficedula motacilla of Brisson. 
It is not known that there are any structual characters by which the 
Wagtails may be separated from the Pipits, except that the former have 
longer tails in comparison with their wings than the latter. In the general 
style of coloration there is, however, a great difference between the two 
genera. There are two extreme types of coloration in the Wagtails, be- 
tween which are several intermediate ones. In one extreme the upper 
parts are black or grey, the throat and breast black, and the remainder of 
the underparts white; in the other extreme the upper parts are olive- 
green and the underparts yellow. On the other hand the prevailing 
colours of the Pipits are brown, more or less spotted above and below. 
The Wagtails are found throughout the Old World, with the exception 
of the Australian Region; but one species crosses Behring’s Straits into 
Alaska. This genus contains about thirty species and subspecies, of which 
eight are European ; of these, five are included in the British list. 
The Wagtails frequent open and well-cultivated districts, the banks of 
streams, and pastures; they are most frequently seen on the ground, 
where they run with great ease, continually vibrating their tails. Their 
flight is very undulatory, and their powers of song are very feeble. They 
feed, so far as is known, upon insects and small shellfish. Their nests 
are built upon the ground or in holes in rocks and buildings; and their 
eggs vary from bluish white to brown in ground-colour, profusely spotted 
with brown or grey of various shades. 
VOL. If. 0 
