BREWSTER: BIRDS OF THE CAPE REGION, LOWER CALIFORNIA. 169 
Tachycineta thalassina lepida. 
Mus. No. Sex Locality Date Wing Tail 
42,4161 ¢ Sebastopol, Cal. April 19,1885 4.62 1.92 
13,2221 ¢ ¢ xs 20; 1886) “451 1.87 
13,2201 ¢ “ oh ‘ Cant 4.50 1.94 
22 Lae as sf May 26,1885 426 1.90 
6781 ¢& MarinCo., “ Sept. . 3,1878 4.57 1.95 
52551 ¢ ee ee <6 April 16,1880 4.53 1.86 
53361 ¢ Oe “ March 30,1883 4.52 1.98 
6791 ¢ Sees S Sept. 93,1878 4.43 1.83 
1 ¢ Huachuca Mts., Arizona May 24,1888 4.58 1.89 
45,5161 ¢ Brit. Columbia April 12,1888 4.80 1.80 
47,3631 od Sumas, a s May 65,1897 4.72 2.00 
45,5151 & Chilliwack, “ a April 9,1891 4.50 1.80 
21,9461 4 Pinos Altos, Mexico June 8,1888 4.50 1.90 
15,4992 og Deer Creek, Col. July 10,1871 4.54 1.99 
15,4972, o a ss sf ee 4.51 1.75 
15,4982 o - ss ss seese 4.50 1.90 
15,4962 ¢o “f ‘ “s a pe oa 4.45 1.80 
2 ¢ Nicasio, Cal. May 9,1879 4.78 1.98 
33,2992 ¢ ce < ‘ $6 AE 4.70 1.95 
Average, 4.55+ 1.90+ 
6751 @ Mill City, Col. May 24,1877 4.54 1.89 
5,8991 @? Cienega Station, Arizona April 16,1881 4.28 1.79 
6761 2 Marin Co., Cal. ‘June 12,1877 4.10 1.73 
33,2982 2 Nicasio, Cal. April 12,1879 4.41 eae 
Average, 4.338+  1.78+ 
The Violet-green Swallow of the Cape Region furnishes an interesting illus- 
tration of the recognized fact that isolated, non-migratory birds are given to 
having shorter wings than those which regularly perform extended journeys, 
for in respect to the length of the wing it is almost if not quite as much smaller 
than the form which breeds in the regions lying further to the northward 
(i. e. California, Oregon, Washington, and British Columbia) as the latter is 
smaller than true thalassina of the Mexican table-land still further to the 
southward. This difference, shown in the foregoing tables of measurements, 
is the only essential one which I am able to find between lepida and brachyp- 
tera. In the material which I have examined it appears to be not only marked 
but constant. There can be little question, however, that the two birds really 
come together and intergrade in the central portions of the Peninsula. 
1 Collection William Brewster. 
2 Collection Mus. Comp. Zool. 
