OF THE BRITISH ISLANDS.. 87 



measure on an average 2'i inches in length by 1*3 inch in 

 breadth. Incubation lasts from twenty-one to twenty-three days. 

 Both parents assist in this duty, and the young are soon able to 

 leave the nest and take to the water with the old birds. They 

 dive well, and seek to elude enemies by hiding in any nook or 

 cranny when pursued. According to Stevenson and other 

 observers, odd eggs of the Waterhen are sometimes found in the 

 nest of this species. 



Diagnostic Characters.— .^«/«Va, with the general colour 

 slate-black, a white wing bar caused by pale tips to the secondaries, 

 and with a broad white frontal shield. Length, 16 to 18 inches. 



