14 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Microtits pennsylvanicus fontigenus (Bangs). 
The northern form of the common meadow mouse, recently de¬ 
scribed by Mr. Bangs as Microtus fontigenus, 1 is abundant at Nepi- 
gon and Peninsula Harbor. It is probable that this form replaces 
31. pennsylvanicus pennsylvanicus in the Hudsonian zone through¬ 
out eastern North America. . At present, however, it is known 
from Lake Edward, Quebec, and the north shore of Lake Superior 
only, localities about 700 miles apart. 
At both Nepigon and Peninsula Harbor 31icrotus pennsylvanicus 
fontigenus occurs in great numbers and in very varied situations. 
At Nepigon it was especially numerous in the fields near the Hud¬ 
son Bay post and among the rank weeds along the railroad 
embankment south of the station. At Peninsula Harbor it was 
common everywhere except in the thickest woods. In general the 
habits of this vole are the same as those of its larger southern rela¬ 
tive. It appeared to be less inclined to form runways, however, 
and on the railroad embankment at Nepigon its presence was indi¬ 
cated merely by little collections of cut and partly eaten grass stems. 
In a marshy caribou pasture near Peninsula Harbor, on the other 
hand, the turf was honeycombed by a labyrinth of tunnels inhabited 
by field mice, lemmings, and shrews. 
I have compared a series of over forty 31icrotus pennsylvanicus 
fontigenus from the north shore of Lake Superior with Mr. Bangs’s 
specimens from Lake Edward, Quebec. They agree in all essential 
characters, though in the Lake Superior specimens the audital bullae 
average a trifle larger and the incisive foramina are just appreciably 
longer. While 3ficrotus pennsylvanicus fontigenus differs notice¬ 
ably from 31. pennsylvanicus pennsylvanicus in its smaller size, 
longer, more silky fur, and in certain slight though constant cranial 
characters, as pointed out by Mr. Bangs, the two forms are so closely 
related that it appears most reasonable to treat them as subspecies 
of one wide-ranging species rather than as completely segregated 
types. It must be admitted that no clearly intermediate specimens 
have yet been seen, but these are almost certain to occur in the 
region between North Bay and White River, possibly as far east 
as Chapleau. 
1 IToc. Biolog. Soc. Washington, March 9, 1896, vol. 10, p. 48. 
