286 FALCO GYRFALCO. 



wliicli is connected with the third by a rather large basal web. 

 On the first toe are five, on the second ten, on the third eighteen, 

 on the fourth ten scutella. Claws large, strong, well curved, 

 somewhat compressed, flattened and marginate beneath, taper- 

 ing to a fine point. 



The plumage is compact. The space between the bill and 

 the eye is covered with short bristle-tipped plumelets. The 

 wings are long and pointed, of twenty-five quills ; the first 

 quill ten-twelfths of an inch shorter than the second, which is 

 longest, and exceeds the third by a quarter of an inch, the 

 fourth two twelfths shorter than the first, which has the inner 

 web abruptly attenuated toward the end ; the second also at- 

 tenuated, but without a notch, as is the third in a less degree. 

 The secondaries are rather short, and most of the outer have a 

 terminal sinus or slight notch on the inner web. Tail long, 

 straight, slightly rounded, of twelve broad feathers, which at 

 the end taper to a point. 



Bill very pale blue, at the end darker, at the base pale 

 yellow ; cere, superciliary ridge, and edges of eyelids yellow ; 

 feet pale yellow, the bases of the digital scutella blue ; claws 

 bluish black. The general colour of the plumage is white ; 

 the forehead, cheeks, throat, tibial feathers, abdomen, and 

 lower and upper tail-coverts unspotted. On the rest of the 

 lower parts each feather has a small guttiform greyish-brown 

 spot. The tips of the bristles about the base of the bill are 

 dusky. On the upper part of the head and neck each feather 

 has a linear-lanceolate streak ; on the back and wings each 

 has a subterminal cordate, generally pointed, or sagittiform 

 spot of dusky-grey. The quills and their coverts are barred 

 with that colour ; the outer primaries greyish-black toward 

 the end, and with the bars on their inner webs not extending 

 to the margin. The tail is white, with the exception of seven 

 spots toward the edges of both webs of the two middle feathers. 

 These spots are not all exactly opposite to each other, some of 

 them being alternate. 



Length to end of tail 21 inches ; bill along the ridge 1/^ ; 

 wing from flexure 151 ; tail 9 ; tarsus 2^ ; hind toe H, its 

 claw l:i ; second toe l/g, its claw 1^^^ ; third toe 2, its claw 

 1 ; fourth toe Ij^^, its claw ^§. 



