COLYMBID. 545 
loses again about October or November: it appears 
to be rather earlier in attaining its full summer 
plumage, if such it is, than the Northern Diver, for 
a bird in perfect full plumage in my collection was 
shot at Exmouth as early in the year as the 28th of 
March. The bill is bluish horn; the irides red; the 
top of the head and back of the neck streaked longi- 
tudinally with black and white; the face, sides of the 
neck and chin a beautiful pale slate-grey; fore part 
of the throat red; back and scapulars very dark 
dusky, nearly black, with a very few small white 
spots; rump and tail-coverts the same, but the white 
spots are smaller and rather more frequent; wing- 
coverts the same, but instead of the spots each 
feather is edged all round except the tip with white ; 
the primary quills are dark dusky; flanks and thighs 
dusky, tipped with white; all the under parts are 
pure white; the legs, toes and webs dark brown— 
like those of the Northern Diver, they are paler 
inside, where they are not exposed to the light. 
Another bird in my collection, also shot at Exmouth, 
but in the winter, and to all appearance an adult 
bird, has the top of the head and back of the neck 
like the first mentioned; the back and rest of the 
upper parts very dark, nearly black, very distinctly 
speckled with white—the white spots are larger and 
much more numerous than in the other bird; there 
are a few dark marks in the middle of the throat; 
with this exception the chin, throat and all the rest 
3A 
