334 J. LeConte—Ancient Glaciers of the Sierras. 
middle. This crescentic transverse ridge connecting with the 
main lateral ridges is evidently a terminal moraine, behind 
which the lake has accumulated. Through this, of course, the 
stream has cut its way. Beyond this terminal moraine there Is 
a marsh. Below this the lateral moraines are again seen to 
send off each a branch which, curving, again meet. It 1s an- 
other terminal moraine, behind which was probably formed first 
a shallow lake, which has been gradually filled up with sedi- 
ment and converted into a marsh. Beyond the marsh is a meadow 
which has been evidently formed in the same way, for below 
the meadow there are evidences of still another terminal 
moraine. 
From the summit of any of the volcanoes near by on the 
ale a fine bird’s-eye view of all I have described is obtained. 
he long lateral moraines and the three or more terminal mo- 
raines By mabe the lake, marsh, and meadow, are seen at one 
glance. 
ing out on the plains from the gorges bf the mountains, some 
of far greater height and length than those described. They 
are all no doubt moraines, but I have only observed them at 4 
distance. : 
‘hitney, in the first volume of the Geological Survey of Cali- 
fornia (p. 437), speaks of the lakes in Bl Cafion, but as 
cribes sa ee to the S hpnetp of water behind terminal 
moraines. But it is evident that the upper one is a pure roc 
basin ; its lower rim is not a terminal an but isa feautifully 
