BIRDS—HIRUNDINIDAE—H1RUND0 TIIALASSINA. 
311 
As a general thing specimens of this species from the extreme south of the United States, as 
Brownsville, Texas, and those from the western coast are considerably smaller than those from 
Pennsylvania. 
The female is duller in color than the male; the metallic tints of the bach much more obscure 
and less continuous. Tbe shade is rather more violet. 
The young male of the year (164,) is entirely of a sooty grayish brown above and on the 
wings, with the faintest possible trace of purplish reflection on the head and back. The color is 
somewhat like that on the back of Cotyle riparia, but darker. 
It is not at all improbable that careful comparisons of many specimens may ultimately prove 
the existence of distinct species of white-bellied swallows on the two sides of the continent. 
The difference in size will be shown by the table of measurements. In two California specimens 
before me, one has the same greenish gloss as Pennsylvania skins ; in the other the lustre is 
more of a steel blue. 
List of specimens. 
Catal. 
No. 
Sex and 
age. 
Locality. 
When collected. 
Whence obtained. 
Orig. 
No. 
Length. 
Stretch 
of wings. 
Wing. 
2097 
$ 
Carlisle, Pa_-_ 
April 12, 1845 .. 
S. F. Baird. 
6. 25 
12. 25 
5 00 
2341 
O 
__„do__ 
May 24, 1845_ 
5. 33 
12. 25 
4. 25 
1164 
O (J 
Aug. 22,1843... 
5. 83 
12. 50 
4. 67 
2342 
Q 
May 24, 1845... 
Northern Illinois_ 
R. Kennicott__ 
4663 
$ 
Matamoras, Mex_... 
Lieut. Couch _ _ 
4664 
4665 
$ 
4666 
$ 
4667 
$ 
5913 
s 
Steilacoom, W. T_ 
June, 1855 _ 
J. G. Cooper__ 
6. 00 
12. 50 
6016 
$ 
1854. 
88 
5. 00 
12. 50 
4 75 
6015 
s 
__ - _ 
Shoal water bay, W. T.. 
May 2, 1854 .... 
J. G. Cooper_ 
76 
5.00 
12. 50 
4.75 
5494 
s 
Petaluma, Cal_ 
E. Samuels_ 
712 
4200 
San Francisco, Cal_ 
Winter, 1854 _ 
R. D. Cutts_ 
HIRUNDO THALASSINA, Swain son. 
Violet-Green Swallow. 
Hirundo thalussina, Swainson, Taylor’s Philos. Mag I, 1827, 365 .—Aud. Orn. Biog. IV, 1838, 597; pi. 385.— 
Ib. Birds Am. I, 1840, 18G ; pi. 49. —Cassin, lllust. I, 1855, 245.— Brewer, N. Am. Oology, 
1,1857, 102; pi. v, f. 74. (Egg.) 
Chelidon thalassina, Boie, Isis, 1844, 171. 
Tachycineta tlialassina, Cabanis, Mus. Hein. 1850,48. (Type.) 
Sp. Ch.—T ail acutely emarginate. Beneath pure white. Above soft velvety green, with a very faint shade of purplish 
violet concentrated on the nape into a transverse band. Rump rather more vivid green ; tail coverts showing a good deal of 
purple. Colors of female much more obscure. 
Length, 4.75 ; wing, 4.50 ; tail, 2. 
Hub. —Rocky Mountains to Pacific ; south to Mexico ; east to Saltillo, Mexico. 
