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THE DIVING BIRDS — POGOPODES. 



the grayish white coloration of the occiput and nape characteristic of this species. The com- 

 parative measurements of arcticus and pacificus may be best shown by the following figures : — 



Mr. Kennicott met with the l'aritic form of the Black-throated Diver breeding on 

 the edges of lakes, and mentions finding a nest in water about eighteen inches deep, 

 in grass at the edge of a long, narrow lake. It consisted of a mere pile of hay, like 

 the nest of a Grebe, with the top very little above the surface of the water. Another 

 was in the grass at the edge of a lake, built like a Grebe's nest, but larger. 



Mr. Bannister speaks of this bird as being common at the Island of St. Michael's. 

 Mr. Dall states that the skins are much sought for by the natives, and are obtained 

 while the birds are breeding in the shallow lagoons, where they cannot dive, and 

 where they are netted in great numbers ; the eggs were obtained at Fort Yukon. 

 Mr. Boss mentions finding a few birds of this species on the Mackenzie Biver. 



Dr. Cooper speaks of this form as quite common in the winter as far south as San 

 Diego. From the fact of his having killed a female in May, he thinks that it may 

 breed in the mountain lakes, though not yet observed there, in summer. In its habits 

 it closely resembles the U. immer ; but he has never known it to scream or to utter 

 any sound. This silence may be attributable to the season. 



Mr. MacFarlane found it breeding in considerable numbers in the vicinity of Fort 

 Anderson. The nests were usually on the borders of small lakes, sometimes a mere 

 hole in the turf with a slight sprinkling of feathers therein, or a mere piece of turf 

 without lining, hardly above the level of the water, or a mass of decayed vegetable 

 matter with a slight depression in the centre, on the edge of and in the water. In 

 another instance the nest was composed of a piece of turf about two feet square, on 

 the border of a small lake, and nearly four feet from the shore. A hole had been 



