- 
480 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
Adults in winter—Head and neck white, the hindneck tinged 
with pale gray, the auricular region and a crescentic space immedi- 
ately in front of eye dusky grayish; otherwise as in summer. 
Young.—Upper parts pale gray, the feathers more or less tipped 
with pale clay color or dull buff, this‘sometimes nearly uniform on 
back and scapulars, where the gray is mostly concealed, the pileum 
and hindneck, as well as back and scapulars, sometimes streaked with 
dusky, but oftener immaculate; a blackish crescentic spot immediately 
in front of eye, and a dusky grayish suffusion on upper portion of 
auricular region, forming a more or less distinct postocular stripe; 
rump, upper tail-coverts, tail, and wings nearly uniform pale gray; 
remiges deeper, more silvery, gray, the secondaries and proximal 
primaries tipped or terminally margined with white; rectrices darker 
gray subterminally and tipped with white or buffy; under parts 
immaculate white; bill dusky brownish, the mandible dull brownish 
orange, dusky terminally; legs and feet varying from dull reddish 
brown to dusky brown (in life), the soles more reddish. 
Downy young.—Upper parts light grayish buff with several large 
and tolerably well-defined dusky irregular spots on posterior lalf of 
head, a distinct dusky stripe down each side of hindneck and upper 
back, the wings, rump, and flanks with rather distinct large spots of 
dusky; under parts white, tinged with grayish on sides of throat; 
bill brownish inclining to orange (in life) on mandible; legs and 
feet brownish orange (in life). 
‘Adult male-—Wing, 288-338 (301); tail, 104.5-135.5 (114.8); 
exposed culmen, 37-42 (38.7); tarsus, 27-36 (29. 5); middle toe, 
20-25.5 (21.4). 
Adult female.—Wing, 275-313 (292.3); tail, 103-127 (112.2); ex- 
posed culmen, 35-38 (36.5); tarsus, 27.5-32 (29.1); middle toe, 20-22.5 
(20.8).2 
2 Ten specimens. 
: Ex- 
Locality. Wing. | Tail. | POSed lrarsus, | Middle 
men. 
MALES, 
One adult male from Spain (Seville, October)................. 324 119 BBe We oes. 25. 5 
One adult male from Australia (@.n. macrotarsa).............. 338 135.5 42 36 25 
Six adult males from Atlantic and Gulf coasts of United States.| 298.8 |. 115.2 38.3 28.7 21 
One adult male from Bahamas (Andros Island, May) 316 125 39 30 21.5 
One adult male from Vera Cruz (Pajaros, April 25)..... --| 293 118 37 29.5 21 
Two adult males from Guerrero (Cayacal, April12)............ 303.7 | 107.2 40.7 32 22.7 
FEMALES, 
One adult female from Spain (Coria del Rio, April 29)......... 298 118 37 32 22. 5. 
One adult female from Russia (Volga River)..................- 313 i an eres 31 22 
Four adult females from coast of Virginia (May)............... 296.7 | 116.1 36 29 20.5 
Four adult females from coast of Mississippi (July)............ 290.2] 108.2 37.1 29. 9° 21.2 
One adult female from Bahamas (Rum Cay, July IO) eeccieac cee 289 119.5 35 28.5 20.5 
One adult female from Guerrero (Cayacal, April 12)............ 286 105. 5 37 27.5 21 
