MAMMALIA. 12a 
-[89.] 5. Arvicoza Boreatis. (Rich.). Northern Meadow-Mouse. 
Mouse, No. 15. ForstEr, Phil. Trans., 62. p. 380 ? 
Arvicola borealis. Ricwarpson, Zool. Journ., No. 12, April, 1828, p.517. 
Awinnak. Doc-nrrs Inprans. 
A. (borealis) pentadactylus, awriculis vellere conditis, cauda caput subequanti, corpore villosissimo badio nigroque subter 
cinereo. 
Northern Meadow-Mouse, with a strong thumb-nail, ears concealed in the fur ; tail about as long as the head; fur very 
long and fine ; on the back chestnut colour mixed with black, on the belly gray. 
This animal was found in abundance at Great, Bear Lake, living in the vicinity 
of the Arvicola xanthognathus, and having similar habits. It very much resembles 
the Arvicola Novoboracensts in size and general appearance; but, on comparing 
them with each other, the A. borealis is seen to have a rounder and smaller head, 
a less prolonged upper jaw, shorter ears, and ashorter and differently clothed tail. 
Tt may also be distinguished not only from the A. Novoboracensis, but also from 
the A. xanthognathus and A. Pennsylcanicus, by the form of its thumb-nail, which, 
instead of being thin, obtuse and rounded, lying closely on one side of a little 
tubercle, is larger, strap-shaped, and projects from the extremity of a minute 
rudimentary thumb. It has its outer and inner surfaces alike in being rather 
convex, and a small obtuse point projects from its truncated end. The form of the 
thumb-nail allies this animal very closely to the Norway lemming, and to one or 
two species of American lemming ; but its claws are smaller and more compressed, 
and apparenily not so well calculated for scraping earth as the broader claws of 
the lemmings. It may, however, be considered as an intermediate link between 
the two sub-divisions of the genus arvicola, and may without inconvenience be 
ranked either as a true meadow-mouse or as a lemming. 
DESCRIPTION. 
The Northern-Meadow Mouse has the dentition and usual form of the campagnols, with a 
moderately large head, a convex forehead, and a short but acute nose projecting beyond the 
incisors. ‘The eyes are small, and the ears, which, toward their margins, are thinly clothed 
with hairs of the same colour with the adjoining parts, are low, rounded, and shorter than the 
surrounding fur. The body and head are clothed with fur, which is very long in proportion to 
the size ofthe animal. The fur on the upper parts is shining blackish-gray, from the roots to 
the tips, some of which are yellowish or chestnut-brown, some black. The hairs with black 
tip sare the longest, and are equally distributed amongst the others, giving the whole a dark 
