NON-INDIGENOUS BRITISH BIRDS. 275 



near and the beaches of the Arctic Ocean. Mac- 

 Farlane's nest was discovered on the tundra about ten 

 miles west of FrankHn Bay, and was merely a hollow 

 scantily lined with dry grass and leaves. Thirteen years 

 afterwards, almost to the very day (24th June), Capt. 

 Feilden found another nest close to Cape Union in 

 Grinnell Land. This nest was made on a ridge of gravel 

 several hundred feet above sea-level, and was a slight 

 hollow in the centre of a bent-down willow plant, lined 

 with a few dead leaves and withered catkins. 



Range of egg colouration and measurement : 

 The eggs of the Sanderling are four in number. They 

 are somewhat pyriform in shape, smooth in texture, and 

 buffish-olive in ground colour, densely mottled, and 

 spotted with pale olive-brown, and with underlying 

 markings of ink-gray. Two distinct types occur, so far 

 as our knowledge extends at present. One of these 

 has the markings thickly congregated on the major half 

 of the ^^g ; the other is more uniformly marked over 

 the entire surface. Average measurement, 1*4 inch in 

 length, by ro inch in breadth. Incubation is performed 

 by both sexes, but the duration of the period is 

 unknown. 



Diagnostic characters : The peculiar character of 

 the markings (small and mottled), combined with the 

 shape and size, readily distinguish the eggs of the 

 Sanderling from those of allied species. 



