52 
The young are born, it is thought, in early July. As already stated, 
a female taken on July 4, at Nettilling lake, contained nine large embryos. 
On June 15, at cape Dorset a specimen (No. 848) held eight large embryos 
and another (No. 849) seven of somewhat smaller size. Comparatively 
few of the specimens secured bore young. 
If traps are not regularly tended, the lemmings eat the trapped speci- 
mens. Their food, however, consists largely of grasses. 
A back lemming was observed, on June 9, at cape Dorset, to leap 
into a pool of water, swim to the other side, briskly mount the bank, and 
disappear at a run into a burrow. It was all done so unconcernedly that 
without doubt the animal was in the habit of taking to the water, but 
this was the only occasion on which a lemming was seen resorting to the 
water. Considering the sodden ground they frequently occupy, such as 
the tundra-swamp west of Nettilling lake, it would not be surprising if 
they were semi-aquatic in habit. 
The first record of the occurrence of trimucronatus on Baffin island 
was by Allen and Copeland (1924, pp. 8-9) in connexion with the MacMillan 
specimens from Bowdoin Harbour district. These authors write: “The 
most interesting of the small mammals is the lemming, previously not 
known to occur farther northwestward than the Melville peninsula and the 
shores of Boothia Felix So far as we can ascertain, its presence 
has not been known previously on any of the islands of the Arctic archi- 
pelago”. The National Museum of Canada has specimens from Victoria 
island (collected in 1918), Banks island (collected in 1915), and Digges and 
Big islands, Hudson strait (collected in 1884-85). The comparatively 
wide range of the species is indicated by Allen and Copeland (1924, p. 9) 
who wrote: “Externally the adults agree in every particular with specimens 
from northern Mackenzie, kindly loaned to us by the United States Bio- 
logical Survey and taken to represent typical trimucronatus. 
Measurements of Lemmus trimucronatus fro?n Various Localities 
in Baffin Island 
No. 
Date 
Locality 
Sex 
Length 
Tail 
Hind foot 
4909 
Aug. 
19, 
1923. . 
Strathcona sound 
9? 
Mm. 
105 
Mm. 
12 
Mm. 
18 
4910 
tt 
19, 
1923.. 
ii 
<? 
102 
12 
18 
4911 
tt 
19, 
1923. . 
a 
& 
106 
14 
18 
4912 
tt 
31, 
1923.. 
Ponds inlet 
9 
118 
14 
18 
4913 
tt 
31, 
1923. . 
(( 
c? 
109 
12 
18 
6020 
June 
7, 
1925.. 
Nettilling lake 
d 1 
132 
10 
15 
6021 
ii 
11, 
1925. . 
U 
9 
120 
10 
17 
6024 
July 
4, 
1925. . 
it 
9 
137 
10 
18 
6034 
Aug. 
27, 
1925. . 
a 
9 
124 
14 
20 
6037 
Oct. 
7, 
1925. . 
Pangnirtung fiord 
if 
9 
127 
20 
22 
6038 
ii 
7, 
1925.. 
cT 
125 
16 
20 
6040 
U 
8, 
1925. . 
a 
& 
122 
12 
21 
6042 
it 
10, 
1925.. 
tt 
9 
135 
15 
19 
6043 
tt 
10, 
1925. . 
ii 
9 
115 
12 
17 
6044 
a 
10, 
1925. . 
ii 
d” 
115 
13 
18 
6045 
u 
10, 
1925. . 
ii 
9 
115 
12 
19 
6049 
u 
12, 
1925. . 
it 
c? 
112 
12 
18 
6050 
a 
12, 
1925. . 
tt 
9 
120 
14 
19 
6051 
it 
13, 
1925. . 
tt 
9 
125 
13 
19 
6052 
(t 
13, 
1925. . 
tt 
9 
112 
12 
18 
6053 
tt 
15, 
1925. . 
If 
9 
120 
13 
18 
6054 
tt 
15, 
1925. . 
tt 
9 
124 
14 
19 
6055 
a 
15, 
1925. . 
it 
c? 
121 
13 
19 
