CHAPTER II. BLUEBIRDS 



FAM. SAXICOLID^E 



RECOGNITION of the family Saxicolidce is purely a conven- 

 tional matter, in which most ornithologists tacitly agree to 

 follow each other upon no better ground than that of precedent. 

 The characters of the only genus with which we have here to 

 do will be found beyond under head of Sialia, no definition of 

 the whole group being attempted none being, perhaps, prac- 

 ticable. The limitation of the group fluctuates with different 

 authors, especially on the side next to Turdidce. As usually 

 constituted, it contains about a dozen genera and upward of a 

 hundred species, which agree in possessing 10 primaries, of 



which the first is very short or 

 spurious, and booted tarsi. It 

 is essentially an Old World 

 group, represented in the west- 

 ern hemisphere only by the 

 characteristic American genus 

 Sialia, with three species, and 

 by a single species of the typi- 

 cal genus Saxicola, some of the 



FIG. 14.-Details of structure of Saxicola. details Of the external form of 



which are illustrated in fig. 14. This species, the well-known 

 Stone Chat or Wheatear of Europe, 8. cenanthe, occurs sparingly 

 in Greenland, along the North Atlantic coast of America, and 

 also in Alaska ; it is generally considered as simply a straggler 

 from the Old World, but it is apparently not rare in Labrador, 

 in which country there is reason to believe it breeds. 



Genus SIALIA Swainson 



CHARS. Primaries 10, the 1st spurious and very short. 

 Wings pointed, the tip formed by the 2d, 3d, and 4th quills. 

 Tail much shorter than the wings, emarginate. Bill about half 

 as long as the head or less, straight, stout, wider than deep at 



