284 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 



rocky shores are numbers of seafowl whose breeding area does not of 

 course closely coincide with that of land birds. 



The few species of characteristic Arctic land birds are not evenly 

 distributed over the barren area. They are most numerous, at least 

 in point of species, in the more northern part. Thus in the region 

 about Ungava, Ptarmigan, Rough-legged Hawks, Gyrfalcons, Snowy 

 Owls, Horned Larks, Snow Buntings, Lapland Longspurs, Pipits, and 

 Wheatears are all breeding birds, but as we follow the Arctic coastal 

 strip south, the Ptarmigans, Snow Buntings, and Lapland Longspurs 

 soon become less common, and over most of the southern portion of 

 this area, the Rough-legged Hawks, Horned Larks, and Pipits are the 

 only Arctic birds that seem to be of general distribution. In addition 

 to these species, however, should be mentioned the Savanna Sparrow, 

 which, with the Horned Larks and the Pipits, is one of the most 

 characteristic of the barren-ground birds of Labrador. To us who 

 are accustomed to seeing this bird in the grassy meadows of the east- 

 ern United States, it seems strangely out of place on the wind-swept 

 moors of this bleak coast. 



Hudsonian and Canadian zones. — These two zones, inasmuch 

 as they are separated by no sharp line of demarcation, may best be 

 considered together. Although the upper limit of the Hudsonian 

 fauna coincides closely with that of the stunted tree growth, the 

 transition from the Hudsonian to the Canadian is so gradual that 

 no definite boundary can be traced between them. At the upper 

 limit of the Hudsonian, where it borders upon the Arctic zone, the 

 trees become greatly dwarfed and exceedingly dense and scrubby. 

 White and black spruces, balsam firs, and larches grow in matted 

 thickets from three to six feet high with outlying clumps of even less 

 height occurring in sheltered spots as "islands" within the Arctic 

 area. Back from the barren coastal strip in the sheltered valleys, 

 ravines, and river bottoms these trees attain a more vigorous growth 

 so that along the shores of Hamilton Inlet and southward they reach 

 here and there the height of twenty-five or thirty feet. In addition 

 to the conifers, there are occasional clumps of stunted paper birch and 

 aspen, while along the streams there are thickets of alder and willow. 

 Inland, "the forest is continuous over the southern part of the penin- 

 sula to between latitudes 52° and 54° .... To the northward of lati- 

 tude 53°, the higher hills are treeless and the size and number of the 

 barren areas rapidly increase. In latitude 55°, more than half the 



