BLACK-THROATED GREEN WARBLER. 
DeNDROICA VIRENS. 
Char. Male in spring : above, bright olive ; line on sides ot head rich 
yellow ; wings and tail dusky ; wing-bars and outer tail-feathers white ; 
beneath, white tinged with yellow; throat and chest rich black. Male in 
autumn, female, and young : similar, but black of throat mixed with yellow, 
sometimes obscured. 
Nest. On the border of heavy woods, in fork of coniferous tree 30 to 
50 feet from the ground; of twigs, grass, etc., lined with hair and down. 
Eggs. 3-4; white or creamy white wreathed around larger end with 
spots of brown and lilac; 0.65 X 0.50. 
This rather rare species arrives from its tropical winter- 
quarters in Pennsylvania towards the close of April or begin- 
ning of May. About the 12th of the latter month it is seen in 
this part of Massachusetts ; but never more than a single pair 
are seen together. At this season a silent individual may be 
occasionally obsen'ed, for an hour at a time, carefully and ac- 
