o southern Greenland. Guillemots are larger birds than the
Murrelets (length 13 inches) and their plumage is entirely different.
This species in summer is entirely black except the wing coverts which
are white. The bases of the greater coverts, however, are black, this
generally breaking the white mirror as it is called. The under surfaces
of the wings are white. Legs red. These birds breed abundantly on the
rocky islands and high cliffs along the coast. Soon after the first of
June the eggs are laid in the crevices of the rocks and sometimes upon
the bare ledges. Two or three eggs make the set. The ground color is a
pale bluish or greenish white and the markings are various shades of
brown and black. Size 2.40 x 1.60. Data.--Grand Manan, June 15, 1896.
Two eggs laid in a cavity back of large boulder. No nest. Collector, D.
H. Eaton.

[Illustration 030: Xantus Murrelet. Mandt's Guillemot.]
[Illustration: Bluish white.]
[Illustration: Black Guillemot.]
[Illustration: left hand margin.]

Page 29

28. MANDT'S GUILLEMOT. _Cepphus mandti._

Range.--North Atlantic coast, more northerly than the preceding,
breeding from Labrador to northern Greenland.

The bird differs from the Black Guillemot only in having the bases of
the coverts white also. The nesting habits and eggs are identical. They
nest in colonies of thousands and place the eggs upon the bare rock with
no attempt at nest building. Generally the eggs are in the crevices so
as to be difficult to get at. Size 2.30 x 1.55. Data.--Depot Island,
Hudson Bay, June 6, 1894. Two eggs laid on bare rocky ground. Collector
John Comer.

29. PIGEON GUILLEMOT. _Cepphus columba._

Range.--The Pacific Coast of North America, breeding from southern
California northward. This bird is very similar to the Black Guillemot
except that the under surfaces of the wings are dark. They breed
abundantly on some of the islands of Bering Sea and a few of them nest
on the Farallones. They lay their two eggs on the bare rock in dark
crevices. The color is grayish or pale greenish blue and the markings
are brown and black with paler shell markings of lilac. Size 2.40 x
1.60. Data.--S. Farallone Islands, Cal. Two eggs laid on gravel at the
end of a burrow, about two feet from the entrance and 285 feet above the
sea level. Collector, Claude Fyfe.

30. MURRE. _Uria troile troille._

Range.--North Atlantic coasts and islands, breeding from Bird Rock
northward. Murres are similar in form