LO ae 
500. 
501. 
FALCONIDA — FALCONINZ: FALCONS. 533 
Labrador into U.S. in winter. (F. labradora, Aud., folio pl. 196.) I have seen it perfectly 
dark, —no markings whatever. 
F. islan/dicus. (Lat. form of Icelandic.) IceLAND GyRFALCON. Resembling 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 aud southern Greenland, straggling in winter into the N. E 
U.S. 
Ee 
. Wha iis 
VE, 
ig 
Fig. 376. — Lanner Falcon, } nat. size; not distinguishable in the cut from the Prairie Falcon. (From Brehm.) 
F. can/dicans. (Lat. candicans, whitening.) GREENLAND GYRFALCON. The extreme 
form, averaging when adult as white as a snowy owl. Head, neck, and under parts pure white, 
with few dark touchesif 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. 
