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, Gyrfaleons, 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 
