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, y2-3'5 inches; 
diam., 1-9-2 -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. COLYJMBUS SEPTENTRIONALIS. 
Colymbus septenirionalis, Linn. Syst. Nat. i. p. 220 (1766); 
Macgill. Brit. B. v. p. 301 (1852); Dresser, B. Eur. 
via. p. 621, pi. 628 (1876); B. O. U. List Brit. B. 
p. 202 (1883) ; Saunders, ed. Yarrell’s Brit. B. iv. 
p. 1 12 (1884) ; Seebohm, Hist. Brit. B. iii. p. 412 (1885) ; 
Saunders, Man. Brit. B. p. 699 (1889); Lilford, Col. Fig. 
Brit. B. part xviii. (1891J. 
(Pla/e CXIF.) 
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 
