546 Birds of Colorado 
96 Naso, H. W. American Rough-legged Hawk, with photograph. 
Nidol., 1v., 1896, p. 15. 
97 Nasu, H. W. Nest and Eggs of the Arkansas Goldfinch. Nidol., 
Iv., 1897, p. 29, with photograph. 
90 Nixon, J. P. A series of Eggs of the Rock-Wren. Orn. and Ool., 
xv., 1890, p. 21. 
88 Norris, J. P. A Series of Eggs of Sitta pygmea. Orn. and Ool., 
_ xir., 1888, p. 173. 
02 OsERHOLSER, H.C. A Review of the Larks of the Genus Otocoris. 
Proc. U.S. Nat. Mus., xxrv., 1902, pp. 801-884, pls. 43-45, 
and 4 maps. : 
04 OpERHOLSER, H. C. A Revision of the American Great Horned 
Owls. Proc. U.S. Nat. Mus., xxvir., 1904, pp. 177-192. The 
Colorado subspecies referred to Asio magellanicus occidentalis. 
05 OBERHOLSER H. C. The Forms of Vermivora celata. Auk, xxu., 
1905, p. 242. Description of Vermivora (= Helminthophila) 
celata orestera, the Rocky Mountain Region form of the Orange- 
crowned Warbler. 
06 OsERHOoLsER, H. C. The North American Eagles and their 
Economic Relations. Bull. No. 27, Biol. Surv. U.S. Dept. Agric. 
pp. 1-31. Washington, 1906. 
07 OBERHOLSER, H. C. A New Agelaius from Canada. Auk, xxiv., 
1907, pp. 332-336. Agelaius p. arctolegus and A. p. fortis occur 
in Colorado. 
90 OspurN, W. Nesting of the Grebes (Podilymbus podiceps). 
Orn. and Ool., xv., 1890, p. 68. 
93 OsspurnN, W. Birds of Rare Occurrence in Northern Colorado. 
Science, xxu., 1893, p. 212. Zonotrichia coronata first recorded. 
01 Oscoop, W. H. New subspecies of North American Birds. Auk, 
xvi., 1901, pp. 179-185. The White-tailed Ptarmigan of 
Colorado, separated as a distinct subspecies (Lagopus leucurus 
altipetens). 
86 Pearce, G. D. Water Ousel or American Dipper. Sunny South, 
Ool., 1., 1886, p. 8. 
10 Pree, Z. M. An Account of Expeditions to the Sources of the 
Mississippi, and through the Western Parts of Louisiana to 
the Sources of the Arkansaw, Kans, La Platte and Pierre Juan 
Rivers, performed by order of the Government of the United 
States during the years 1805, 1806, and 1807, etc., etc. Phila- 
delphia, 1810, 8vo. The portion relating to Colorado contains 
allusions to the Pheasant (ic. Dusky Grouse), Turkey, Raven, 
Magpie, and Carolina Parrot. Coues’ edition, published in 
New York, in 3 vols., in 1895, is quoted in the records for these 
species. 
