780 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
Winter plumage.—Coloration as in summer, including white head- 
plumes, but corneous supranasal horn and gonydeal ridge wanting, 
the former, however, indicated (at Jeast in freshly killed specimens) 
by a more or less pronounced swelling, covered by membrane.* 
Young.—Similar to winter adults, but white head-plumes wanting 
and bill smaller and darker in color. 
Downy young.—Uniform sooty grayish brown, slightly paler on 
under parts of body. (Very similar to the corresponding stage of 
Lunda cirrhata but rather lighter in color and with more slender bill.) 
Adult male.—Wing, 175-183 (177.8); tail, 42.5-60.5 (55); exposed 
culmen, 32.5-36 (34); tarsus, 27-30 (28.2); middle toe, 39.543 
(40.4).2 
Adult female.—Wing, 169-181 (175.6) ; tail, 52-56.5 (55.5); exposed 
culmen, 32-39 (34.7); tarsus, 27-29 (28); middle toe, 3841.5 (39.9).° 
Coasts and islands along border of northern Pacific Ocean; breed- 
ing from Sitka, Alaska, southward to Washington (Smiths Island, 
Puget Sound; Protection Island), formerly to Farallon Islands, Cali- 
fornia, and on Kuril Islands;* southward in winter to southern Cali- 
fornia (Santa Barbara; San Diego, Dec., Jan.; Santa Catalina Island, 
Dec., March), Lower California (San Miguél Island; Cerros Island, 
Juné), and northern Japan (Hakodate; Tsushima; Otarunai, near 
Sapporo; Nagasaki), and southeastern Siberia (Usuri Bay; Vladi- 
vostok). 
Alca monocerata Patuas, Zoogr. Russo-Asiat., ii, 1826, 362 (Cape St. Elias to 
Kodiak Island, Alaska). 
Chimerina monocerata REICHENBACH, Natatores, 1850, pl. 6, figs. 2706, 2707. 
aSee Henshaw, Auk, ii, 1885, 387, 388. 
> Six specimens. 
Ex- 
Locality. Wing. | Tail. | P°S€4 | Tarsus.| Middl 
_Ien. 
MALES, 
Two adult males from California. ..............20.0020 cece eee 177.5 58 33 27.5 39.5 
Two adult males from Alaska... ............00.0 cece cece ecco ee 176.5 56.7 33.7 28 40.5 
One adult male from Kuril Islands-...........2.-..2-..002000+ 183 58 36 30 43 
One adult male from Japan. ............- 0.02 e cece eee cee e ees 176 42.5 34.5 28 39.5 
FEMALES. 
One adult female from California.............020-2.ceeeee eee ee 178 53.5 37 29 41.57 
One adult female from Puget Sound..............2..-.-0- Siete 177 52 33 29 41 
Three adult females from Alaska. ..............-000.ececececeee 173 55 33.2 27 39 
One adult female from Japan cc.necivevensesesevidendnndansccce 176 52.5 39 29 40 
¢ Almost certainly breeding on some of the intervening islands also. 
