Range. - Coasts and islands of the North Atlantic, breeding from Maine northward to 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 crev-ices 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.