336 
BULLETIN OF THE NATURAL HISTORY SOCIETY. 
along these valleys sortheasterly into the North Pole Branch, of 
which, perhaps, this lake forms the morphological head. 
The outlet of Dunn Lake forms a very pretty torrent over the 
boulders for a quarter of a mile or more, when it becomes a rough 
bouldery stream which empties into a series of long boulder- 
bordered deadwaters or ponds, the Tendon Ponds, lying in a flat 
basin. The uppermost of these receives also the outlet of a series 
of very pretty clear-water little lakes ( MacDougal Lakes, of which 
the uppermost, Senda Lake, is especially attractive), extending 
close up under Thunder Mountain, and fed by mountain streams 
from its slope. Below the deadwaters the stream flows with little 
fall, largely over a gravelly and sandy bed, down to Gover Lake, 
receiving the outlet of the pretty Garrett Lakes and the import- 
ant Patchel Brook. This brook is formed by the confluence of 
two large branches, one coming down between Thunder and 
Ridge Mountains, forming a mountain torrent which has cut 
deeply into the mountain rocks, and another which rises on the 
Upper Graham Plains and has cut the very remarkable deep 
gorge which I have described in an earlier note (No. 64). There 
is no doubt, I think, that the latter branch is the true morpholo- 
gical head of the Walkemik Stream, and that its pre-glacial pre- 
decessor extended across Lower Graham Plains, through Gover 
Lake and along the present Walkemik valley to near its mouth, 
forming one of the primitive northwest-southeast series of rivers 
radiating from the Central Highlands. Both of the branches of 
Patchel Brook leave the mountain gorges abruptly and cross a 
heavily-wooded boulder-strewn plain in very irregular courses 
difficult to follow. Gover Lake, 1292 feet above the sea, the 
drainage centre of the basin, is an irregular shallow lake, with 
bog and boulder margin, and muddy bottom. In addition to the 
main Walkemik stream it receives three brooks. The first is a 
small, clear spring-brook from the east. The second, Middle 
Brook, runs along the southwest margin of the Lower Graham 
Plains. The third is Pot-hole Brook, which rises apparently on 
the margin of the plateau, and in its course to Gover Lake flows 
beside, and in some part through, the most extensive and finely- 
developed series of glacial sink-holes that I have seen anywhere 
