49 
along the coast of Ellesmere island, in Lancaster sound, and in Wellington 
channel. J. C. Ross (1835, p. 21) states that the animal was occasionally 
seen in the northern part of Prince Regent inlet. They are tolerably 
numerous in Foxe channel and Frozen strait (Low, 1906, p. 281) and in 
Roes Welcome. Tremblay (1921, p. 176) states that walruses are plentiful 
at Igloolik in Fury and Hecla strait, where they feed on clams and 
small fishes found in the shallow waters surrounding the numerous islands. 
They are found on both shores and on the islands of Hudson strait. Four 
hundred years ago walruses occurred as far south as Magdalen islands in 
the gulf of St. Lawrence, now cape Chidley marks their southern limit along 
the Atlantic seaboard. In Hudson Ray region, they formerly were 
found as far south as Paint islands in James bay, but now their southern 
limit is Belcher islands. 
14. Lemmus trimucronatus (Richardson), back lemming. 
Eskimo: Awingak; Avingak , according to Hantzsch. 
The lemming at times is more abundant than any other land mammal 
of Baffin island. It is subject to periodical variations in numbers, which, 
as is probably the case with Lepus americanus of the mainland, may be 
due to bacterial invasions resulting from over-crowding by the lemming. 
The diseased condition, when it arises, results in the destruction of almost 
the entire population. It spreads rapidly, but, as indicated by the observ- 
ations recorded below, does not appear simultaneously over all Baffin island. 
The following information was recorded during the 1923 Canadian 
Arctic Expedition. Signs of lemmings were seen in varying abundance at 
every point visited except Beechey island. No fresh signs were noted at 
Craig harbour, Ellesmere island, but the police had seen a few trails during 
the preceding winter and spring. At Dundas harbour, Devon island, 
fresh trails and burrows, probably made by Dicrostomyx groenlandicus, 
were observed. At Eskimo point, Strathcona sound, fresh signs of lemmings 
were abundant in the comparatively luxuriant vegetation bordering a 
stream; several specimens were secured at this place. At Ponds inlet, 
lemmings were comparatively numerous on an abandoned, Eskimo village 
site. Many of the animals were trapped and all these proved to be tri- 
mucronatus. They occupy small burrows in the partly frozen soil, con- 
nected by a network of trails. Inland, on the tundra, were seen many 
signs usually old and many consisting of small, round nests of grass. At 
Pangnirtung, Cumberland sound, old signs were exceedingly numerous 
both along the shore and well up the mountain slope to an elevation of at 
least 1,700 feet, but not even one lemming was seen or trapped during a 
stay of eleven days, though on September 18, after a fresh fall of snow, a 
new lemming trail was seen. 
From the preceding statements, it will be noted that although little 
colonies of lemmings continued to flourish in northern Baffin island, the 
species was almost extinct at Pangnirtung in the south. Sergeant Wight 
stated in 1924, that for the past two years lemmings had been very scarce 
at Port Burwell, though they had been amazingly abundant at different 
times in earlier years. 
Returning to Pangnirtung on July 22, 1924, fresh signs of lemmings 
were first observed on August 23, on Blacklead island, where a small 
colony, presumably of trimucronatus, was located. At Pangnirtung old 
signs were abundant everywhere up to altitudes of at least 1,000 feet, but 
