Plate IX 



1. Black-throated Blue Warbler, Adult Male. 4. Cerulean Warbler, Adult Male. 



2. Black-throated Blue Warbler, Adult Female. 5. Cerulean Warbler, Adult Female. 



3. Black-throated Blue Warbler, Young Male. 6 .Cerulean Warbler, Young Male. 



(one-half natural size.) 



