92 
Ridgway on the Plumage of Gy r falcons. 
For a fuller record of Mr. Henshaw’s additions, which were first 
reported in the “ American Sportsman,” see Rep. Geog. and Geol. 
.Sur. West of 100th Merid., Vol. Y, Zoology, Chap. III. 
The following new genera have been proposed for North Ameri- 
can Birds since 1874 : — 
1. Peucedramus, Coues, apud Henshaw, Rep. Geog. and Geol. Expl. 
W. 100th Merid., Y, 1875, 202. Type Sylvia olivacea , Giraud. 
2. Iridoprocne, Coues. Birds Col. Yall., 1878, 412 (subgenus); Bull. 
U. S. Geol. and Geogr. Surv., Y, Feb., 1879, 74, foot-note (genus). 
3. Amphispiza, Coues. Birds of the Northwest, 1876, 234. — Type, 
Ernberiza biliniata , Cass. 
4. -SIchmoptila, Coues. Bull. U. S Geol. and Geogr. Surv. Terr., IY, 
Feb., 1878, 48 (— Leptoptila, Swain., 1837, not of Lesson, 1831). — Type, 
JE. jamaicensis (Linn.). jEchmoptila, however, Dr. Coues now decides 
must give place to Engyptila, Sund. (see below, p. 100). 
DESCRIPTION OF THE ADULT PLUMAGE OF HIEROFALCO 
GYRFALCO OBSOLETUS * 
BY ROBERT RIDGWAY. 
Having been permitted, through the kindness of Mr. Yennor, to 
examine the specimens described in “ Our Birds of Prey,” f under 
the title of “ Falco sacer , Forst.,” one of which is the type of “ Falco 
dawsonis,” Hall, together with a third example, obtained subsequent 
to the publication of the above-named work, these descriptions 
are presented as being of probable interest from the fact that no 
* Hierofalco gyrfalco obsoletus. 
Falco obsoletus , Gmel., S. N., I, ii, 1788, 268 (based on Plain Falcon , Pen- 
nant, Arct. Zool., II, 1781, p. 208. 
Falco labradora , Aud., B. Am., 1831, pi. cxcvi. 
Falco gyrfalco var. labradora , Rldgw., in B. B. & R., Hist. 1ST. Am. B., Ill, 
1874, 117. 
Falco dawsonis , Hall, Canadian Naturalist and Geologist, YII, 1862, p. 68. 
“ Falco sacer , Forst.,” Yennor, Our Birds of Prey, 1876, 23, pi. iv (nee 
Forst.* 1772). 
t Our Birds of Prey, or the Eagles, Hawks, and Owls of Canada. By Henry 
G. Vennor, F. G. S., of the Geological Survey of Canada. With 30 Photo- 
graphic Illustrations by William Notman. R. Worthington, 750 Broadway, 
New York. Montreal : Published by Dawson Brothers, 1876. Royal 8vo, 
pp. i-viii, 1-154, pll. xxx. 
