244 
U. S P R. R. EXP AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
In this species the wings are short and broad ; the tertials in the closed wing longer than 
the secondaries, and about .45 of an inch shorter than the primaries; the wing considerably 
rounded, the first quill intermediate between the fourth and fifth, the second longest. The tail 
is moderately graduated, the lateral feathers .15 of an inch shorter than the middle one. 
It is quite possible that in the full plumaged male the entire throat may be blaclr, as there 
is a tendency to this in some specimens. A fall male (1697) shows the black only on the fore 
breast. 
Authors describe the black feathers of the throat as crenulated (margined) with white. I 
have never seen any specimens (out of about twenty) in which these margins were other than 
ash color. 
The mourning warbler is very similar to the Oporornis agilis, and is only to be distinguished by 
the smaller size, much shorter, and more rounded wings, longer legs, and shorter toes, and other 
generic characters. The adult males are easily separated by the decided black of the throat 
and absence of white ring round the eye in G. Philadelphia. The females are much more closely 
related, both having the pale ring round the eye. The longer and more pointed wings of 
agilis will distinguish them ; the relations to G. macgillivrayi will be pointed out under that 
species. 
A female (2906) has a strong tinge of buff yellow on the throat. 
List of specimens. 
Catal. 
No. 
Sex. 
Locality. 
When collected. 
Whence obtained. 
Orig. 
No. 
Length. 
Stretch 
of wings. 
Wing. 
Remarks. 
1499 
Carlisle, Pa_.^ 
May 26, 1844 
S. F. Baird. 
5. 50 
7. 75 
2. 41 
1697 
Sept. 6, 1844 
5. 75 
8. 00 
2. 50 
1011 
$ 
__do__ 
Sept. 24, 1843 
_do_ 
5. 33 
8. 16 
2. 58 
1024 
O 
----- -do_...... 
May 26, 1843 
5. 25 
7. 75 
2. 41 
103? 
O 
_do_ 
May 30, 1843 
5. 33 
7. 66 
2. 16 
2273 
O 
------ do_----- 
May 17, 1845 
5. 16 
7. 75 
2. 41 
427? 
O 
_do_ 
May 28, 1841 
_do_ 
5. 41 
7. 66 
O 
South Illinois_ 
May 11, 1841 
R. Kennicott_ 
7515 
Independence, Mo - 
Dr. Cooper_ 
45 
5. 00 
6. 00 
2. 50 
Iris and bill brown, 
feet pale brown.. 
GEOTHLYPIS MACGILLIVRAYI, Baird. 
Macgillivray’s Warbler. 
Sylvia macgillivrayi, Audubon, Orn. Biog. V, 1839, 75 ; pi. 399. (Sylvia Philadelphia on plate.) 
Trichas macgillivrayi, Aud. Syn. 1839, 64.— 1b. Birds Amer. II, 1841, 74 ; pi. 100. 
Sylvia tolmioei, Townsend, J. A. N. Sc. VIII, 1839, 149, 159. (Read April, but the volume really not published 
till 1840.) 
Sylvia tolmiei, Townsend, Narrative, 1839, 343. 
Trichas tolmiaei, Nuttall, Man. I, 2d ed., 1840, 460. 
Sr. Ch.—H ead and neck all round, throat and fore part of the breast dark ash color ; a narrow frontlet, loral region and space 
round the eye (scarcely complete behind) black. The eyelids above and below the eye (not in a continuous ring) white. The 
feathers of the chin, throat, and fore breast really black, with ashy gray tips, more or less concealing the black. Rest of upper 
parts dark olive green, (sides under the wings paler ;) of lower, bright yellow. Female with the throat paler and without any 
black. Length of male, 5 inches ; wing, 2.45 ; tail, 2.45. 
Hab .—Pacific coast of North America, south to Gulf of California and across to Monterey, Mexico. In Rocky mountains to 
Fort Laramie? (Dr. Cooper.) 
