90 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
DESCRIPTIONS OF SOME BIRDS SUPPOSED TO BE UNDESCRIBED, 
FROM THE COMMANDER ISLANDS AND PETROPAULOVSKI, COL- 
LECTED BY DR. LEONHARD STEJNEGER, U.S. SIGNAL SERVICE. 
By ROBERT RIDGWAY. 
The following apparently new species form part of a fine collection of 
birds from the Commander Islands and the vicinity of Petropaulovski, 
Kamtschatka, lately received at the National Museum from Dr. Leon- 
hard Stejneger, U. S. Signal Observer at Bering Island. The writer was 
requested to descibe them in case they appeared, after due investigation, 
to be new. 
1. HALLZTUS HYPOLEUCUS Stejneger, MS. 
Sp. cH.— Young 2 (No. 89127, collector’s No. 1055, Bering Island, May 
15, 1882). Ground color of pileum, nape, upper back, rump, with lesser 
and middle wing-coverts dirty white, spotted with grayish brown, the 
spots of the latter color being chiefly subterminal, but often occupying 
the tips of the feathers; upper part of rump with white largely pre- 
dominating; greater wings-coverts and longer scapulars uniform dusky, 
bordered terminally with mottled dirty grayish white; tertials uniform 
slate-dusky ; upper tail-coverts mottled dusky terminaly, mottled white 
basally ; remiges uniform brownish black; rectrices blackish dusky, the 
inner webs much mottled with pale grayish and buffy white. Side of 
head with a broad and distinct stripe of nearly uniform brown, occupy- 
ing the entire orbital, and auricular regions. Entire lower parts white, 
all the feathers with distinct dusky shafts; those of throat streaked 
with pale brown, those of jugulum and upper breast with a large ter- 
minal spot of dusky, many of the feathers of sides and abdomen with 
small and usually indistinct brown terminal spots; thighs and crissum 
dirty white, the feathers with dusky terminal spots, these largest on 
crissuin, and on upper and inner portions of thighs coalesced so as to 
form the predominating color. Underside of wing white, spotted with 
dusky. Bill dusky, inclining to yellowish at tip and base, the rictus 
yellow; “iris faint yellowish white”; feet deep yellow, claws black. 
Wing 24.50 (ends of primaries much abraded), tail 13.50, culmen 2.25, 
depth of closed bill 1.50, tarsus 3.60 (naked portion in front only 1.75, 
after raising the feathers), middle toe 3., hind claw 1.80. 
This eagle ts perhaps the eastern representative of H. albicilla, al- 
though the latter, according to Sharpe (Cat. B. Brit. Mus., i, p. 304), 
occurs “in Kamtschatka, the Aleutian Islands, and Japan,” and also 
in China, “‘as faras Amoy.” Itis barely possible, however, that all ref- 
erences to H. albicilla in the above-named countries may in reality apply 
to the present bird or (especially so far as the Aleutians are concerned) 
to H. leucocephalus, the latter occurring abundantly, not only throughout 
the Aleutian chain, but also in Bering Island, where, according to Dr. 
Stejneger, it breeds. 
