ORNITHOLOGICAL EXPLORATIONS. 21 



Birds of the year of the two forms, calif ornica and arra^ may be distin- 

 guished thus : Californica has the culmen less curved, the gonys long, 

 much longer than half the culmen, and the bill lower; the greater un- 

 der wing-coverts are gray with white edgings ; the shafts of the first 

 primaries above are very light, nearly white ; the color of the upper 

 head and neck is more tinged with brownish. Arra has the culmen more 

 curved, the gonys short, about half the length of the culmen, and the 

 bill higher ; the greater under wing-coverts darker and uniform gray 

 without white edgings; the shafts of the primaries dark brownish; 

 the color of the upper head and neck more glossy and black. 



7. Cepphus columba Pallas 



1790.— fJna gnjlle Latham, lud. Orn., II, p. 797. 



1826. — Cepphus columha Pall., Zoogr. Ross. As., II, p. 348 (part.). — Turner, Auk, 1885, 

 p. 159. — Uria c. Cassin, U. S. Explor. Exped. Ornitb., p. 346 (1858).— 7fL, iu 

 Baird's B. N. Amer.,p. 912 (1858).— Jd., Pr. Acad. Pbilada., 1862, p. 323.— 

 SwiNH., P. Z. S., 1863, p. 330.— Dall & Baxnist., Tr Chicag. Acad., I, 

 1869, p. 309.— FiNSCH, Abb. Brem.Ver., Ill, 1872, p. 78.— Dall, Avif. Aleut. 

 Isl. Unal.eastw., p. 11 (1873).— 7rf., Avif. Aleut. Isl. westUnal., p. 10 (1874).— 

 Taczan., Oru. Fauu. Vost. Sibir., p. 73 (1877).— /d., Bull. Soc. Zool. France, 

 1877, p. 51.— Id., ibid., 1883, p. 398.— Blakist. & Puyer, Tr. As. Soc. Jap- 

 , X, 1882, p. 91.— Bean, Pr. U. S. Nat. Mus., 1882, p. 172.— Nelson, Cruise Cor. 

 win, p. 117 (1883).— Hartlaub, J.f, Om., 1883, p. 285. 



1832.— Uria grylle Kittlitz, Isis, 1832, p. 1105 {neo luis.). —Id., Denkw. Raise, I, pp. 

 273, 2*^1.— Cepphus g. Whitely, Ibis, 1867, p. 210. 



This is the '■'■ KajurTca'''' of the natives, who do not recognize them by 

 the Russian name '■'' SvistunJ'' 



The Pigeon Guillemot is a very common bird all around the shores of 

 both islands, although not by far so numerous as several other Alcidw, 

 for instance, Uria arra and Luncla cirrhata. They are mostly found in 

 single pairs. It has been denied that they ever congregate in large 

 flocks, but this is not absolutely correct, for on several occasions I ob- 

 served flocks of them, especially on June 4, 1883, when I visited the 

 small island Toporkof, opposite the village of Bering Island. The 

 whole islet was covered with hundreds and hundreds of birds in their 

 full black summer plumage, collected into larger and smaller flocks, 

 generally consisting of about fifty or more. 



In 1883 the first arrivals were noted on the 14th of March. On Cop- 

 per Island a nest containing two eggs (the usual number) was taken 

 June IG, measuring 58 by 41'"'", and 58 by 40""° (U. S. Nat. Mus. No. 

 21777 ; L. Stejneger No. 2211). 



Downy young just out of the shell were collected at the same place 

 on July 20, 1883. They are covered with a black down, and are in every 

 respect similar to those of Cepphus grylle. 



