194 BLACK-THROATED DIVER, 
centre of the webs yellowish olive. The accom- 
panying wood-cut will shew the form of these regular 
l 
spots in the Black-throated (No. 1) and Great North- 
ern Divers (No. 2). A specimen killed in winter (in 
the plumage of the Lesser Imber) has the tint of the 
