BIRDS OF NORTH AND MIDDLE AMERICA. 239 



as long as wiiig, slightly graduated, the four middle rectrices abruptly 

 longer than the rest, contracted distally, with tips narrowly rounded; 

 rectrices 12. Tarsus shorter than middle toe with claw (but equal 

 to or shghtly longer than middle toe without claw), less than one- 

 fourth as long as wing, continuously scutellate anteriorly and poste- 

 riorly; bare portion of tibia very short (much less than half as long 

 as tarsus), non-scutellate; lateral toes decidedly shorter than middle 

 toe, the outer slightly longer than the inner; no web between middle 

 toe and either of the anterior toes. 



Coloration.— Pi'OKnn&l secondaries (next to tertials), tips of greater 

 wing-coverts, lateral upper tail-coverts, and most of under parts 

 (except anteriorly) white; rump, median upper tail-coverts, and 

 middle rectrices dusky; rest of upper parts grayish, the feathers 

 darker centrally and faintly glossed with purplish, in winter plumage, 

 more or less variegated with rusty and black in summer; head and 

 neck nearly plain brownish gray, the chest with feathers gray 

 centrally broadly margined with white in winter, the head and neck 

 more or loss streaked and chest spotted or clouded with blackish in 

 summer. 



Range. — Northern portions of northern hemisphere. (Two species.) 



KEY TO THE SPECIES AND SUBSPECIES OP ARQUATELLA. 



a. Summer adults and young with little, if any, rusty or cinnamon-rufous on 

 upper parts, the former without any dusky patch or extensive clouding on 

 breast. (Northern Europe, northeastern North America, and northwestern Asia.) 



Arquatella maritima (p. 239). 



aa. Summer adults and young with much rusty or cinnamon-rufous on upper parts, 



the former with a conspicuous patch or extensive clouding of dusky on breast. 



(Arquatella ptilocnemis .) 



b. Larger and much lighter colored ; wing averaging 126.5 in male, 129.2 in female; 



culmen averaging 30.4 in male, 33 in female. (Islands of Bering Sea, north 



of Aleutian chain; coast of Norton Sound, etc., in migration.) 



Arquatella ptilocnemis ptilocnemis (p. 244). 

 bb. Smaller and much darker colored; wing averaging 117.6 in male, 120.2 in 

 female; exposed culmen averaging 26.3 in male, 29.6 in female. (Com- 

 mander Islands, Kamchatka; Aleutian and Shumagin islands, Alaska; 

 coast of Norton Sound, Kotzebue Sound, etc., in migration.) 



Arquatella ptilocnemis couesi (p. 247). 



ARQUATELLA MARITIMA (Brunnich). 



PURPLE SANDPIPER. 



Adults in summer (sexes alike). — General color of upper parts 

 dusky, the head and neck narrowly and rather indistinctly streaked 

 with light huffy, the scapulars and interscapulars sooty black or 

 blackish brown faintly glossed with bronze or purplish bronze and 

 irregularly spotted or indented along edges with dull buff and nar- 

 rowly margined terminally with whitish; rump, upper tail-coverts, 



