292 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
cut the channel above (e, 38, 52, 54). One at Cedarville is more than 
a square mile in area. Most striking of all are the deep rock gorges at 
Syracuse, which mark outlets of glacial Lake Warren. One of these is 
two miles long, 8,000 to 10,000 feet wide at the bottom, and 125 to 150 
feet deep, with nearly vertical walls ; another is a limestone gorge, with 
a cataract cliff 160 feet high, at the foot of which is a deeply excavated 
pool (e, 60). i 
In New England, the outlets of temporary lakes are not nearly so 
well defined. In the case of Lake Nashua, Crosby has discovered what 
he considers to be evidence of outlet scouring in the pass at Clinton, — 
a sag in the divide, which must have been used as a spill-way, judging 
from the height of sand plains in the Nashua valley near by. Professor 
Crosby says: “ This is an ideal outlet 
every indication of a strong stream flowing swiftly down around Snake 
Hill into the valley of North Brook. In the lower part of its course, 
especially, this stream washed away all the fine parts of the till, and its 
path is now strewn with thousands of residuary boulders. That this is 
the work of a Jong-continued torrent, and not of some transitory cloud- 
burst, is proved by the pot-holes to be seen in the bed at North Brook 
at West Berlin, in situations which make it well-nigh impossible that 
they can have been formed by the modern brook” (a, 318). 
Similar traces of spill-ways are to be seen in some of the cols in the 
eastern rim of Lake Sudbury, and along the courses of the brooks that 
head in them. A half-mile northwest of Weston station, the contours 
show a forked pass at about 160 feet, occupied by the headwaters of a 
brook and crossed by a road that runs north from the village. Accord- 
ing to the contours, this col is the lowest northeast of the Saxonville 
pass, being probably 10 feet lower than the one south of Weston village. 
narrow, well-defined, and with 
It is therefore a place which deserves critical examination for evidence 
of outlet scouring. 
Going north along the road from the railroad west of Weston station, 
one crosses the western end of a ridge of bed rock with a thin till cover- 
ing. Reaching the southern fork of the brook, one finds west of the 
road a broad swampy area, well wooded and almost flat, at an elevation 
of 163 feet (aneroid). Beginning directly at the road and extending 
east along the line of the brook, is a pavement of boulders so thick as to 
be remarkable even to one not looking for features of the sort. The 
paved zone is about 100 feet wide, and consists of boulders of moderate 
size, as well as a few cobbles. It follows the lowest ground along the 
brook, which is about 3 feet wide. About 300 feet east of the road, the 
