| OBERHOLSER, Notes on N. A. Birds. II. 320 
Dendroica cerulescens cairnsi Coues. 
The status of this race has recently been questioned by Mr. 
C. W. G. Eifrig + on account of two intermediate male specimens 
collected in the Allegheny Mountains of western Maryland; and 
on this basis it is proposed to eliminate the form from the North 
American list.? 
Examination, however, of a large series of birds of this species 
representing both Dendroica cerulescens cerulescens and Dendroica 
cerulescens cairnst indicate that the two current races are clearly 
recognizable. While it is true that the amount of black on the 
back of the male varies considerably in both forms and that males 
from New York and New England occasionally have much black 
on the interscapulum, it is also true that the southern birds have 
on the average a much greater amount of black and are almost 
never entirely without these black markings. There are, however, 
other characters in the male which serve to separate Dendroica 
cerulescens cairnst from Dendroica cerulescens cerulescens, such 
as the darker shade of the bluish ground color of the upper parts, 
especially the pileum, which also is sometimes streaked with black. 
The female of Dendroica cerulescens cairnsi is even more easily 
distinguished than is the male, for it is darker and duller above as 
well as less yellowish on the lower parts, and has the olivaceous 
color of the flanks darker and more strongly contrasted with the 
pale dull yellowish of the middle of the abdomen. In characteriz- 
ing this southern race of the Black-throated Blue Warbler alto- 
gether too much emphasis has heretofore been placed on the 
amount of black on the back of the male, for the subspecies, as 
above indicated, would not fall with this character alone, since the 
coloration of females is undoubtedly the best diagnostic character. 
In fact, Dendroica cerulescens cairnsi is a perfectly recognizable 
race and deserves retention in our list. 
Mr. Eifrig, in the communication above mentioned, has ‘inti- 
mated that the breeding form of this species in the mountains of 
western Maryland is the northern race, Dendroica cerulescens 
1 Auk, XXXII, January, 1915, p. 110. 
2 Cf. Stone, Auk, XX XIII, October, 1916, p. 431. 
