BIRDS OF NORTH AND MIDDLE AMERICA. 289 



PISOBIA COOPERI (Baird). 



COOPER'S SANDPIPER. 



Similar in coloration to P. fuscicollis but summer adult ^ with 

 white of median upper tail-coverts broken by V-shaped marks of 

 dusky, and size decidedly greater. 



Adult male in summer (sex not determined) . — General color of upper 

 parts brownish gray or grayish brown, the feathers blackish centrally or 

 mesially, producing rather large, irregularly cuneate spots on back and 

 scapulars and streaks elsewhere, the latter broadest on crown, where 

 the ground color inclines to grayish buff; a few of the more posterior 

 scapulars slightly tinged with light cinnamon-buff or rusty ochraceous; 

 rump dusky brownish gray, the feathers margined with grayish white 

 and with blackish shaft-streaks; upper tail-coverts white, with 

 irregular sagittate and V-shaped marks of dusky; wing-coverts 

 brownish gray, the smaller with darker centers and blackish shafts, 

 the greater distinctly tipped with white; remiges dusky, the proximal 

 primaries edged basally with white, the proximal secondaries more 

 broadly margined terminally with white; shafts of primaries wliite 

 post-medially, passing into grayish brown basally and terminally; 

 tail light brownish gray, the middle rectrices darker, becoming still 

 darker terminally, the others narrowly margined with whitish; sides 

 of head and neck white or grayish white, faintly tinged with buffy or 

 pale ochraceous and narrowly streaked with dusky, the supraloral 

 region, however, nearly immaculate (minutely and sparsely flecked) ; 

 under parts white, the chin, upper throat, breast, abdomen, and anal 

 region immaculate, the lower throat, foreneck, and chest tinged with 

 buffy and rather densely streaked with dusky, the upper breast, sides, 

 and flanks marked with irregular streaks . (becoming more or less 

 sagittate or hastate on flanks) of dusky, the under tail-coverts 

 with narrow mesial streaks of the same; axillars and most of under 

 wing-coverts immaculate white, the coverts near edge of wing spotted 

 with dusky, the under primary coverts pale gray edged and tipped 

 with wliite; length, about 241,5; wing, 146; tail, 57; exposed culmen, 

 31; tarsus, 29; middle toe, 22.^ 



Long Island, New York (Raynor South, May 24, 1833; only one 

 specimen known). 



o No other phase of plumage is known. 



^ One specimen, the type, No. 5989, coll. U. S. Nat. Mus., Raynor South, Long 

 Island, New York, May 24, 1833; collected by William Cooper. 



The relationship of this bird, the type of which remains unique, is distinctly with 

 P. fuscicollis, from which it could hardly be distinguished but for its decidedly greater 

 size, all its measurements exceeding the maximum of them of P. fuscicollis. It needs 

 no comparison with Canulus canutus, the coloration, in ioto, and the proportions being 

 very different. 



40017— 19— Bull. 50, pt S 20 



