MOTACILLA. 193 



and the Goldcrests. It is impossible to guess what species was considered 

 typical by Linnaeus ; 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. II. 



