284 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
Zool., lix, 1915, 384 (Demarcation Point, n. e. Alaska, breeding; Herschel 
Island, Aug.; Providence Bay, n. e. Siberia, June 11; habits). 
Erolia bairdii Hartsrt, in Hartert, Jourdain, Ticehurst, and Witherby, Hand-list 
of British Birds, 1912, 176; Novit. Zool., xxiii, 1916, 91 (Africa; Siberia; crit.). 
Tringa maritima (not of Briénnich) Russet, Expl. Far North, 1898, 259, part 
(Herschel Island, 3 specs., July 13 to Aug. 14).@ 
PISOBIA FUSCICOLLIS (Vieillot). 
e 
BONAPARTE’S SANDPIPER. 
In summer plumage (only) resembling P. bairdi, but readily 
distinguished by the white (instead of dusky) median upper tail- 
coverts and much more broadly streaked as well as less buffy (nearly 
pure white) chest. 
Adults in summer (sexes alike).—General color of upper parts light 
grayish brown or brownish gray, more or less tinged on crown, back, 
and innermost scapulars with light rusty or cinnamon, the feathers 
of pileum and hindneck, scapulars and interscapulars, black medially, 
producting conspicuous streaks, broadest and more spot-like on dorsal 
region; wing-coverts grayish brown or brownish gray, darker cen- 
trally and paler on margins and with indistinct shaft-streaks of 
dusky, the greater coverts narrowly tipped with white; primary 
coverts and remiges dark brownish gray or dusky (the secondaries 
and proximal primaries somewhat lighter), the secondaries narrowly 
edged with paler and margined terminally (more broadly on proximal 
ones) with dull white; tertials dusky grayish brown medially, passing 
into much lighter grayish brown toward edges; rump dusky grayish 
brown, the feathers margined with pale grayish buffy or buffy gray- 
ish; upper tail-coverts white, the median ones immaculate, or nearly 
so, the lateral ones with a cuneate dusky marking on outer webs; 
tail grayish brown, very dark (dusky) on middle pair of rectrices, 
much paler on lateral rectrices, all narrowly edged with paler and 
(except median pair) narrowly margined terminally with whitish, 
sides of head and neck and entire under parts white, the chin, upper 
throat, breast, abdomen, anal region and (usually ?) under tail-coverts 
immaculate, elsewhere streaked with dusky, the streaks broadest 
(more or less guttate) on chest and sides of breast, becoming gradually 
smaller and narrower anteriorly, the sides and flanks with irregular, 
more or less hastate, spots and streaks of dusky, the under tail- 
coverts sometimes with a few short shaft-streaks of dusky; maxilla 
blackish, more brownish basally, the mandible brownish (in dried 
skins) becoming blackish terminally; iris brown; legs and feet dusky 
brownish (in dried skins). 
Winter plumage.—Wings, rump, upper tail-coverts, and tail as in 
summer; rest of upper parts brownish gray or grayish brown, the 
@ Specimens examined by me.—R. R. 
