142 NORTH AMERICAN FAUNA 61, FISH AND WILDLIFE SERVICE 



ence in color of upper parts between ptilocnemis and couesi is not 

 striking. The under parts of ptilocnemis are much paler with a 

 pale buffy and gray area across the breast, the throat is nearly 

 white and finely spotted, and the streaks on the breast and up- 

 per flanks are narrow and pale. In contrast, the under parts of 

 couesi in the same plumage are heavily and boldly streaked and 

 spotted, thus giving the bird a darker appearance. In the winter 

 plumage also, ptilocnemis is markedly paler than couesi. 



In all races, the measurements of wing and exposed culmen 

 average greater in the female than in the male. Measurements, 

 in millimeters, of 13 males and 19 females of ptilocnemis are as 

 follows : 



Males: wing, 118 to 132 (125.6) ; exposed culmen, 27 to 32 

 (29.3) 



Females: wing, 125 to 136 (129.5) ; exposed culmen, 29.5 to 

 37.5 (33.4) 



The Pribilof sandpiper nests on St. Matthew and the Pribilof 

 Islands, but, as would be expected, it occurs on Alaska Peninsula 

 and the Aleutian Islands in migration. Probably, it winters in 

 this area to some extent. At any rate, among the specimens ex- 

 amined there are at least four from the Bristol Bay region that 

 are referable to ptilocnemis. One of these, a female, was taken by 

 C. L. McKay, at Point Etolin, April 8, 1883. Three others were 

 collected by J. W. Johnson, at Nushagak, April 1 and April 18, 

 1885. McGregor (1906) records that this species was collected 

 on Unimak Island, August 14, 1901, and on Tigalda Island, Au- 

 gust 5, 1901. 



Erolia ptilocnemis couesi 



Attu: Too-loo-goo-yuch 



Atka : Chu-lich'-tah 



Alaska Peninsula: Tsoo-gooch (Wetmore) 



Russian, Commander Islands: Lajdinij kulik (Stejneger) 



In measurements, couesi is quite comparable to maritima and 

 quarta, but all three are definitely smaller than ptilocnemis. The 

 Aleutian sandpiper is decidedly darker than the Pribilof sand- 

 piper — the markings on the under parts are bolder and heavier; 

 the upper parts contain more black and a greater proportion of 

 rusty brown. In this respect, couesi approaches quarta. 



Measurements, in millimeters, of 29 males and 24 females of 

 couesi are as follows : 



Males: wing, 110 to 123 (117.1); exposed culmen, 25 to 34 

 (27) 



