1875.|  .MR.H.E. DRESSER ON FALCO LABRADORUS. 115 
confess that I lean to this opinion also. Should this be the case, 
this species assimilates to F. gyrfaleo, in which the young birds 
are lighter than the adults, rather than to F. islandus and F. can- 
dicans, in which the adults wear a much lighter livery than the 
young birds. The synonymy of this Labrador Jer Falcon will be as 
ollows :— 
FALCO LABRADORUS. 
Falco lubradora, Aud. B. Am. pl. excvi. (1831). 
F. (Hierofalco) gyrfalco, var. labradora, Ridgway, N. Am. Birds, 
ili. p. 117 (1874). 
Hierofalco gyrfalco(L.), Sharpe, Cat. of Accipitres, i. p.416 (1874, 
partim, nec Linn.). 
Mr. Ridgway (North Am. Birds, iii. p. 115) separates the Ameri- 
can Jer Falcon from our European species, calling it MacFarlane’s 
Gerfalcon, Ff. (Hierofalco) gyrfalco, var. sacer, Forst. ; but I feel 
convinced, from an examination of specimens from America, that there 
is no specific or even subspecific difference whatever between them. 
Some time ago Professor Spencer F. Baird courteously forwarded to me 
five specimens of Jer Falcons for examination, viz. :—a, 2 . Fort An- 
derson, Arctic America, 29th May, 1864 (MacFarlane) ; 6, 3. Fort 
Yukon, Porcupine River (Captain F. J. Page); ¢c, 3. Fort Yukon, 
Arctic America, June 1862 (J. Lockhart); d, 2. America; e. Fort 
Nescopee, Labrador (H. Conolly). Of these the first four (a, 4, c, 
and d) are undoubtedly identical with the Norwegian Jer Falcon, the 
fifth (e) being the dark Labrador I’. labradorus above referred to. 
Having a fair series of Jer Falcons in my possesion, I made a critical 
comparison of the four American examples ; and my notes, taken at 
the time, are as follows :— 
Specimen-a, an adult female, compared with a female of F. gyr- 
falco from Quickjock, Lapland. This specimen agrees so closely that 
I cannot trace the least difference either in coloration, measurements, 
or any thing else; and as the two skins are made up much alike, I 
could not well tell them apart, except by the labels. Mr. Blanford, 
who is working with me, is also unable to discern any difference. 
Specimen 64, a male, evidently adult, agrees closely with an old 
male from Lapland in my collection, but has the head darker and less 
streaked with white, and the back is also bluer than that of the Lap- 
land specimen. Doubtless the American bird is the older of the two, 
Specimen c, also a male, agrees tolerably well with my male bird 
from Lapland, but has the head darker. 
Specimen d, a female, agrees very closely with a female from 
Lapland. 
I have marked the specimens with which these American birds 
have been compared, and exhibit them herewith. Unfortunately the 
American specimens have been sent back, or else every one here 
present could have convinced himself of the specific identity of the 
two birds. 
Mr. Ridgway evidently lacked the materials which have been at 
my disposal, or he would doubtless have arrived at precisely the same 
8 
