MOTACILLID^: WAGTAILS AND PIPITS. 



283 



Primaries 10, the spurious 1st primary minute but evident. Head subcrested, but without 

 lateral ear-tufts. Wings long, pointed, the tip formed by the first 3 developed primaries ; 

 inner secondaries long and flowing. Tail emarginate, little more than half as long as wing. 

 Tarsus equal to middle toe and claw. Lateral toes of unequal lengths. Sexes alike. Nest on 

 the ground. Eggs 4-5, thickly speckled. 

 85. A. arven'sis. (Lat. arwwsis, relating to arable land ; ar^MW, a ploughed field.) Sky Lake. 

 TJpper parts grayish-brown, the feathers with darker centres; under parts whitish, tinged 

 with buff across breast and along sides, and there streaked with dusky ; a pale superciliary 

 line ; wings with much whitish edgmg ; outer tail-feather mostly white, the next one or two 

 with white borders. Length of (J 7.50; extent 14.75; wing about 4.00; tail 2.50; bill 

 0.50; tarsus or middle toe and claw 1.00; hind toe 0.45, its claw up to nearly 1.00. ? 

 smaller. This celebrated bird, whose music so often inspires the poet, occurs as a straggler 

 from Europe in Greenland, and also, it is said, in Bermuda and Alaska. It has also been im- 

 ported and turned out in this country, where it may perhaps become naturalized. 



8. Family MOTACILLIDuE • "Wagtails and Pipits. 



BiU shorter than the head, very 

 slender, straight, acute, notched at 

 tip. Nostrils not concealed by 

 feathers, which however reach into 

 the nasal fosste. Rictus not nota 

 bly bristled. Primaries 9, of which 

 the 1st is about as long as the 2d, 

 and the first 3, 4, or 5, form the 

 point; inner secondaries enlarged, 

 the longest one nearly or quite 

 equalling the primaries in the closed 

 wing. Tail lengthened, averaging 

 about equal to the wing. Feet 

 long and slender ; tarsus scutellate, 

 usually longer than the middle toe 

 and claw ; inner toe cleft to the 

 very base, but basal joint of outer 

 toe soldered with the middle one ; 

 hind toe bearing a long and little 

 curved claw (except in Motacilla 

 proper). A pretty well-defined 

 group of one hundred, ohiefiy Old 

 World, species, which may be 



FIG. 156. -Upper, WWte Wagtail; lower, Tellow Wagtail. te™ed terrestrial Sylvias, all liv- 

 (From Dixop.) ing mostly on the ground, where 



they run with facility, never hopping like most Osdnes. They are usually gregarious ; are 

 insectivorous and migratory. They have gained their name from the characteristic habit of 

 moving the tail with a peculiar see-saw motion, as if they were using it to balance themselves 

 upon unsteady footing. They may be distinguished from all the foregoing birds, except 

 Alaudidce, by having only 9 primaries ; from all the following Oseines, by having long flowing 

 inner secondaries ; and from Alaudidm, with which they agree in this respect, as well as in 

 usually having a lengthened, straightish hind claw, by having the tarsal envelope as in 

 Oscimes generally, slender biU, and exposed nostrils. Two subfamilies are generally recog- 

 nized, though the distinctions are scarcely more than generic. 



