Pribilof Islands. — Labrador district. 351 
R. Eschscholtsit, Valeriana capitata, Taraxacum lividum, Pedicularis verticillata. 
Damp sheltered places among the rocks in the interior of St. Paul Island show 
a growth of Claytonia sarmentosa, Viola Langsdorfi, Gentiana frigida. Ferns 
are scarce, but species of Zquisetum (3), Botrychium (1), Phegopteris (1), As- 
Pidium (2), Asplenium (1), Cystopteris (1), and Lycopodium (3) occur, 
Fungi on the Pribilof islands are abundant and varied, especially in and 
around the vicinity of the rookeries and killing grounds of the seals. 
Marine Algal Formation. The algae of these islands are noteworthy both 
in extent and luxuriance. After the heavier gales, the beach will be found 
covered with a vast windrow of kelp and seaweed heaped several feet high 
with the Phaeophyceae most abundant, as Zaminaria longipes, Agarum Turneri, 
Thalassiophyllum clathrus, Nereocystis Luetkeana, Alaria praelonga and Fucus 
platycarpus. The Chlorophyceae and the Rhodophyceae comprise many genera, 
f. e. Zithophyllum, Lithothamnion, Porphyra, Chondrus, Gymnogongrus, Callo- 
phyllis, Rhodophyllis, Ptilota (3 spec.), Odonthalia, Rhodomela, Nitophyllum 
and Delessaria, Constantinea rosa marina. 
2. Sub-Arctic Forest Region of North Canada and Alaska. 
The subarctic zone is situated south of the arctic tundras and has its 
northern limit in the line representing the northern extension of tree growth. 
Its southern boundary is somewhat indefinite, but may be considered in general 
as corresponding with the southern limit of the great northern coniferous forest 
which stretches across the continent, reaching the Pacific Ocean in southwestern 
Alaska. For convenience and because the division is a natural one, four 
districts are recognizable, viz., the Labrador, Hudson Bay, Mackenzie and 
Alaskan districts. These territories are denominated phytogeographically speaking 
districts, because the flora is hardly sufficiently distinct in each to merit the 
use of the proper term region which should be used to distinguish areas of 
the earth’s surface sharply demarcated botanically speaking. 
A. Labrador District. 
Trees and shrubs. The southern half of the Labrador District is included 
in the subarctic forest belt and four coniferous trees may be classed, as for- 
ming the Sub-Arctic Coniferous Formation: Pinus Banksiana (= FP. 
divaricata), Picea alba (= P. canadensis), Picea nigra (= P. mariana), Larix 
americana (= L.laricina). With these species are associated Befula papyri- 
fera, Populus tremuloides, P. balsamifera and in less abundance and of more 
circumscribed range Adies balsamea and on the southeastern margin Thaya 
occidentalis.'-”) The distribution of the forest and the range of its trees depends 
1) Macoun, JoHNn: The Forests of Canada. Transactions Royal Society Canada XI. 1894. 
sect. IV: 3—20. (cfr. Bibliography, p. 55.) 
2) Low, A. P.: Report on Explorations in the Labrador Peninsula Geological SEE of 
Canada. Report I. 1896: 30—39. (cfr. Bibliography, p. 54.) 
