BIRDS HIEUNDINIDAE — HIRUNDO TILALASS1NA. 
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 hack much more obscure 
and less continuous. The 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 Cotyh 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 
2341 
1164 
2342 
4663 
4664 
4665 
4666 
4667 
5913 
6016 
6015 
5494 
4200 
8 
Q 
08 
9 
3 
Carlisle, Pa 
April 12, 1845 
May 24, 1845 
S. F. Baird 
6.25 
5. 33 
5.83 
12.25 
12.25 
12.50 
5 00 
4. 25 
4. 07 
do 
do 
Aug. 22,1843 
do 
May 24, 1845 
do 
8 
8 
8 
8 
8 
8 
8 
do 
. . . 
Steilacoom, W. T 
June, 1855 
1854 
6. 00 
5.00 
5.00 
12.50 
12.50 
12.50 
- do 
Dr. Suckley, U. S. A 
88 
76 
712 
4.75 
4.75 
Shoal water bay, W. T.- 
May 2, 1854 
E. Samuels 
San Francisco, Cal 
Winter, 1854 ... 
K. D.Cutts 
HIRUNDO THALASSINA, Swain son. 
Violet-Green Swallow. 
Hirundo thalassina, Swainson, Taylor's Philos. Mag I, 1827, 365.— Aim. Orn. Biog. IV, 1838, 597 ; pi. 385.— 
Ib. Birds Am. I, 1840, 186; pi. 49.— Cassin, Must. I, 1855, 245.— Brewer, N. Am. Oology, 
1,1857, 102; pi. v, f. 74. (Egg.) 
Chelidon thalassina, Boie, Isis, 1844, 171. 
Tachycineta thalassina, Cabanis, Mus. Hein. 1850, 48. (Type.) 
Sp. Ch. — Tail 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. 
Hah.— Rocky Mountains to Pacific ; south to Mexico ; east to Saltillo, Mexico. 
