RED-THROATED DIVER. 187 



to close in at the end of July, the pair of birds which fre- 

 quented our lake, used to take long flights overhead, flying at 

 a tremendous rate with their long necks outstretched, and 

 looking, in the dim twilight, like large Ducks. 



Mr. Ogilvie Grant writes to me : " As far as I have 

 observed in Scotland, the habits of the Black-throated Diver 

 are quite similar to those of the Red-throated Diver, on 

 which I send you a note, but C. arcticus never breeds on 

 the small lochs. All the nests I have seen have been placed 

 on the sloping banks of islands in the larger lochs, where trout 

 are to be caught in plenty." 



Nest. When in the water itself, the nest is simply made of 

 dead grass and water-plants, but when on land there is no 

 nest at all, or simply a few pieces of fresh sedge. 



Eggs. Two in number. Ground-colour clay-brown or 

 olive-brown, sometimes light or very dark chocolate brown. 

 The black spots are scattered over the whole surface, and are 

 equally distributed, the underlying spots being black or greyish- 

 black, and scarcely to be distinguished from the overlying 

 ones. The dimensions of the eggs axis, 3 -2-3 -5 inches; 

 diam., rq-2'2 overlap those of the Great Northern Diver, so 

 that large eggs of C. arcticus cannot be distinguished from 

 small ones of C. glacialis. Too much care, therefore, cannot 

 be taken in their identification. 



IV. THE RED-THROATED DIVER. COLYMBUS SEPTENTRIONALIS. 



Colymbus septentrionalis^ Linn. Syst. Nat. i. p. 220 (1766); 

 Macgill. Brit. B. v. p. 301 (1852); Dresser, B. Eur. 

 viii. p. 621, pi. 628 (1876); B. O. U. List Brit. B. 

 p. 202 (1883) ; Saunders, ed. YarrelPs Brit. B. iv. 

 p. 112 (1884) ; Seebohm, Hist. Brit. B. iii. p. 412 (1885) ; 

 Saunders, Man. Brit. B. p. 699 (1889); Lilford, Col. Fig. 

 Brit. B. part xviii. (1891). 



(Plate CXI 7.) 



Adult Male. General colour above ashy-brown, with an oily 

 green gloss, the feathers rather blacker in the centre, and 

 sparsely spotted or edged with white, these spots less distinct 



