62 AUKS, MURRES, AND PUFFINS. 



long distance under water with great rapidity, using their wings as 

 well as their feet, and coming to the surface far beyond gunshot 

 range. 



" The Sea Pigeons are met usually in small flocks of half a dozen 

 or more, and generally feed in the open sea at the base of bold cliffs. 

 When on the wing they proceed rapidly and in a straight line, and 

 rarely more than a few feet from the surface of the water. On ap- 

 proaching their nesting-site they rise rather abruptly, and fly directly 

 to their nests " (Chamberlain). 



28. Cepphus mandtii (LicJit.). MANDT'S GUILLEMOT. Resembles 

 the preceding, but the bases of the greater wing-coverts are white instead of 

 black. 



Range. "Arctic regions of both continents" (A. O. IL); in America 

 breeding from Labrador and Hudson Bay northward, migrating southward 

 as far as Massachusetts. 



Nest, in crevices and fissures of cliffs and rocky places. Eggs, two to three, 

 not distinguishable from those of C. grylle, 2'34 x 1'15. 



A more northern species than the preceding, which it doubtless re- 

 sembles in habits. 



30. Uria troile (Linn.). MUKRE. Ad. in summer. Upper parts, 

 wings, tail, and neck all around, dark sooty brown, blacker on the back, 

 wings, and tail ; tips of secondaries, breast, and belly white, the sides more 

 or less streaked with blackish. Ad. in winter and Im. Upper parts, wings, 

 and tail much as in summer; under parts white, the throat more or less 

 washed with sooty brown, the flanks sometimes streaked with brownish, and 

 the feathers of the belly more or less lightly margined with blackish. L., 

 16-00; W., 8-00; Tar., 1-40; B., 1-75; depth of B. at nostril, -50. 



Remarks. Some specimens have a white ring around the eye and a white 

 stripe behind it. They have been named U. ringvia (Brunn.), but it is un- 

 certain as to whether the species is a distinct one or is based on a mere varia- 

 tion of plumage. 



Range." Coasts and islands of the North Atlantic " (A. 0. U.). In North 

 America, breeding from Nova Scotia northward, and migrating southward as 

 far as Massachusetts. 



Nests in communities, side by side on the bare ledges of rocky cliffs. Egg, 

 one, pyriform, varying from pale blue or greenish blue to whitish or buft'y 

 singularly spotted, scrawled, or streaked with shades of chocolate, rarely un- 

 marked, 3-25 x 2-00. 



"These birds begin to assemble on their customary cliffs in Eng- 

 land early in May, and crowd together in such numbers that it is not 

 uncommon to see hundreds sitting upon their eggs on the ledge of a 

 rock, all in a line, and nearly touching each other " (Nuttall). 



" The bird usually sits facing the cliff, holding the egg between her 

 legs, with its. point outward ; if robbed, she will lay at least one more, 



