1924] Swarth: Birds and Mammals of the Skeena River Region 377

erected, and wherever a eabin is built the wood rats take prompt
possession. Where they come from is not evident, their natural
habitations in the poplar woods not being visible, but they are
abundant enough to be a decided nuisance.

Synaptomys borealis dalli Merriam. Dall Lemming Mouse

One specimen (no. 32641) was trapped in a Phenacomys runway
at the summit of Nine-mile Mountain (5500 feet altitude), on August
10. Synaptomys andersoni was described from the interior of British
Columbia to the northward of this regon (Allen, 1903, p. 554), and
S. chapmani from the Selkirk Range of southern British Columbia
(Allen, 1903, p. 555), but there probably is not sufficient material
extant anywhere to determine the validity of these species. The one
iemming mouse at hand from Nine-mile Mountain did not seem to me
sufficiently different from the specimens of dalli in the collection of
the Museum of Vertebrate Zoology to justify the use of another name.
Mr. A. Brazier Howell, to whom J forwarded the specimen, making
comparison with more extensive series in the United States National
Museum, came to the same conclusion.

Phenacomys intermedius Merriam. Kamloops Phenacomys

On the summit of Nine-mile Mountain the extensive masses of false
heather (Cassiope mertensiana) were in places criss-crossed with well
defined runways much like meadow-mouse paths in appearance. These
runways occurred at scattered intervals, usually in patches of cassiope
that were greener than elsewhere, as about the edges of snow banks
or little lakes, and they favored also places where there were breaks
in the ground, such as a little earth bank or some protruding rocks.
They connected tiny holes that ran back into the ground or under
rocks; here and there round nests were found, eight or ten inches im
diameter, made of soft grass and moss, and not unlike birds’ nests in
appearance. At intervals there were piles of faeces, in extraordinary
amount. Fresh faeces and green cuttings of grass and cassiope were
evidence that the runways were in use, but trapping brought meager
results. One Phenacomys, one Synaptomys, and one Evotomys was
the sum total of two weeks’ trapping. The runways I took to be the
work of Phenacomys, for I had never found similar trails elsewhere
where I had trapped the other two species that were taken here.