276 DWELLINGS OF MUSKRAT AND BEAVER—GILPIN. 
zibethicus, Lim.,) is very common over the whole northern part 
of North America. Formezly he was classed with the Beaver, 
but lately more justly, with the sub-family Arvicolinee, or field 
rat. Still his habits, his tail, and his hind foot so allied to the 
lobipes in the class of birds, and webbed by ciliated hairs, causes 
him to stand prominently forward in any classification. But it 
is of his building habits, I wish this paper to be. In our Pro- 
vince they are divided into those who live in holes, and those who 
build. The far greater number live in holes ; not from any dif- 
ference in habit, or form, or species, which I could discover, but 
from an instinctive adaptation of external circumstances. In 
running streams connected with our estuaries, they burrow holes 
in the muddy sides of the stream, the mouths of which are sub- 
merged at high tide, and probably bared at.ebb. These burrows 
must slant upwards, so that the extreme end should lie above 
high-water mark, and here he rudely constructs his sleeping form, 
lining it with dried grass. The tides are too rapid, and the dif- 
ference of level between high-water and ebb, too far as well as 
the angle of the bank-slope too great for bim to found a house. 
Hence though he abounds any where along the deep estuaries of 
the Province connected with Bay of Fundy tides, his house is 
rarely seen. A few years ago one stood solitary in Steel’s pond, 
in the suburbs of Halifax, whilst a pair had sought refuge in 
Griffin’s pond on the Halifax common, making no houses, but 
living in the drains and giving amusement to the many loiterers 
there about, in watching their fluvial gambols, ending with a 
dive, preceded by a splash of water caused by a sharp slap of 
their tail upon its surface. Here we had the dome builders, and 
the dwellers in holes close before us for our study. I think 
I saw a dome near Marshal’s on the second Dartmouth lake, 
and again one at Yarmouth. But in all the wide Annapolis 
valley where they abound, I know none save in Winslow’s 
lake, on the top of the north mountain, as that huge barrier 
of Triassic trap elevated to about six hundred feet, and bound- 
ing the whole north-west or Bay of Fundy edge of our 
Province, is called. There is a narrow valley in the centre 
ridge of this whole formation, with hills on either side ; a few 
