160 RiDGWAY on a new Alaskan Sandpiper. 



Total length, about 10 to 12j inches, extent ll\ to 20j; wing, 5.30- 

 6.00 (5.73); culmen, 2.00-3.00; tarsus, 1.25-1.75 (1.53); middle toe, 

 .90-1.10 (1.00). 



Var. griseus. 



Wing, 5.25-5.90 (5.65) ; culmen, 2.00-2.55 (2.30) ; tarsus, 1.20-1.55 

 (1.35): middle toe, 0.90-1.05 (0.95).* Adult in summer: Abdomen 

 whitish ; breast and sides speckled with dusky. 

 Var. scolopaceus. 



Wing, 5.40-6.00 (5.74); culmen, 2.10-3.00 (2.72); tarsus, 1.35-1.75 

 (1.58) ; middle toe, 0.95 - 1.15 (l.Ol).t Adult in summer : Abdomen uni- 

 form cinnamon, without markings ; breast speckled (usually scantily), and 

 sides barred with dusky. 



ON A NEW ALASKAN SANDPIPER. 



BY ROBERT RIDGWAY. 



The various collectors of the National Museura in Alaska have 

 sent from that country numerous specimens of a Sandpiper which 

 in its winter plumage greatly resembles Arquatella maritima 

 (Briinn.), but is very differently colored in its summer dress. 

 After much search among the older authors I have been unable to 

 find a name for it, and therefore, since it ^appears to be new to 

 science, take pleasure in dedicating it to the well-known author of 

 an excellent " Monograph of the North American Tringefe," J also 

 the original describer of a kindred Alaskan species, the A. ptilo- 

 aieniis of the Prybilov Islands. Following is a description of the 

 new species : — 



Arquatella couesi, Ridgw. — The Aleutian Sandpiper. 



Sp. Ch. — Similar to A. maritima (Briinn.), but averaging slightly 

 smaller, and the plumage appreciably different at all ages and seasons. 

 Adult, breeding dress: Above fuliginous-slate, the feathers of the pileum 

 broadly edged, those of the dorsal region (including the scapulars) widely 

 bordered with rusty ochraceous, or bright cinnamon, (a few of the scapulars 

 and interscapulars tipped with white in some specimens,) the central area 

 of each feather nearly black, or much darker than the wings and rump ; 

 lesser wing-coverts slightly, and middle coverts broadly, bordered terminally 



* Extremes and average of 18 fully adult specimens, 

 t Extremes and average of 40 fully adult specimens, 

 t Proc. Philad. Acad., 1861, pp. 170-205. 



