The appended annotated bibliography supplies, in abstract form, most of the hitherto published information on the geographical distribution of _Rangifer arcticus arcticus_. In its preparation I have included records of Caribou from the Arctic islands north to Lancaster Sound, Barrow Strait, Viscount Melville Sound, and McClure Strait--all approximately in latitude 74° N. This has been done as a matter of having a convenient, well-defined regional boundary, not with any conviction that _arcticus_ has ranged so far to the north in the more westerly islands, especially in recent years, when it is said to have become restricted to the southern fringe of the islands (Clarke, 1940: 98; R. M. Anderson, 1947: 178; Banfield, 1949: fig. 1). The islands north of latitude 74° are doubtless the exclusive domain of _Rangifer pearyi_. It is possible that this species may also occur to some extent on Banks, Victoria, Prince of Wales, and Somerset islands. The typical _R. a. arcticus_, as currently recognized, ranges eastward to Baffin, Salisbury, Coats, and Southampton islands and to the western shore of Hudson Bay. (The animals of the last three islands may be distinct insular forms.) The southern limits of the winter range in northwestern Ontario, central Manitoba, northern Saskatchewan, and northeastern Alberta have been discussed in preceding pages. On the west the range extends to the Mackenzie Delta (formerly), Great Bear and Great Slave lakes, Wood Buffalo Park, and Lake Claire. The timbered country (Hudsonian and Canadian Zones) is practically entirely deserted by the Barren Ground Caribou in mid-summer. At this season, in Keewatin at least, the animals tend to draw away also from the southernmost portions of the Barren Grounds. _References._--Since practically every paper in the entire bibliography presents some data on geographical distribution, only a few, containing more than an average amount of new or summarized information on the subject, have been selected for inclusion in the following list of references: Hearne, 1795; Franklin, 1823; Lyon, 1824; Franklin and Richardson, 1828; Simpson, 1843; Pike, 1917 (1892); Russell, 1898; Preble, 1902; Hanbury, 1904; Amundsen, 1908; Preble, 1908; R. M. Anderson, in Stefánsson, 1913b; Stefánsson, 1913a, 1913b, and 1921; Hewitt, 1921; Jenness, 1922; Rasmussen, 1927; Seton, 1929, +3+; Blanchet, 1930; Critchell-Bullock, 1930; Hoare, 1930; Jacobi, 1931; Clarke, 1940; Manning, 1943a; Wright, 1944; R. M. Anderson, 1947; Manning, 1948; Banfield, 1949 and 1951a. _Distributional maps._--Grant, 1903: map following p. 196; Preble, 1908: pl. 19; Dugmore, 1913: 138; Hewitt, 1921: 57; Seton, 1929, +3+: 60, map 2; Jacobi, 1931: 77, fig. 17; R. M. Anderson, 1934b: 4062, fig. 6; Murie, 1939: 241; Clarke, 1940: figs. 3, 4; Banfield, 1949: 479, fig. 1, and 1951a: figs. 4-10; Anonymous, 1952: 267. ECOLOGY _Habitats_