NATURAL HISTORY. 253 



The beautiful and elaborate nest which this bird constructs 

 is one of its chief peculiarities. It is oval in shape, and 

 entirely closed, except one small hole at the side, just large 

 enough to admit the bird. The exterior of the nest is usually 

 covered with lichens, and it is lined with a thick layer of soft 

 feathers. In this warm and elegant habitation from ten to 

 fourteen eggs are laid. They are small and very delicately 

 spotted. The entire length of the bird is about five inches 

 and a half. 



Sub-family c, Motacillince. 

 MOTACILLA. (Lat. a Wagtail.) 



Yarrellii (Lat. of Yarrell), the Pied Wagtail. 



The WAGTAILS, so named, from the almost incessant vibra- 

 tion of their tails, are exclusively confined to the Old World. 

 The PIED WAGTAIL is the most common of its race. We often 

 see it pass rapidly, with its peculiar dipping flight ; it settles 

 on the ground and wags its tail ; it runs a few paces, and 

 wags its tail again ; pecks at an insect, and its tail again 

 vibrates, &c. It does not hop, like the warblers, finches, 

 &c., but runs with great rapidity, and altogether looks very 

 like a diminutive magpie. Sand banks by the sides of rivers 

 are the usual resort of these birds, where they may almost 

 always be seen, running about by the^water's edge, sometimes 



