FALCONin^ — FALCONINJE : FALCONS. 



533 



Labrador into U. S. in winter. {F. labradora, And., folio pi. 196.) I have seen it perfectly 

 dark, — ^no markings whatever. 

 500. P. islan'dicus. (Lat. form of Icelandic.) Iceland Gyrfalcon. Eesembling F. sacer as 

 above described, and probably not fairly separable ; on an average lighter colored, more ex- 

 tensively white below, the head and neck lighter than the rest of the upper parts. 

 This form occurs in Iceland and southern Greenland, straggling in winter into the N. E 

 U.S. 



Pig. 376. — Lanner Falcon, i nat. size; not distinguishable in the cut from the Prairie Falcon. (From Brehm.) 



SOI. p. can'dicans. (Lat. eamdicans, whitening.) Gkeenland Gybfalcon. The extreme 

 form, averaging when adult as white as a snowy owl. Head, neck, and under parts pure white, 

 with few dark touches if any. Back, wings and tail with white and dusky in about equal 

 amounts, or former rather prevailing, giving the ground color, on which the dark appears in 

 bars, crescents, and cordate spots. Bill and feet light. This form is characteristic of Greenland, 

 straying south in winter; but I know of no case of its occurrence in the U. S. 



