340 
Personal and Scientific News. 
most inclined is certainly correct, but this is a feature common to all 
the geological systems, and I fail to see why there should be any ob¬ 
jection to two or even more groups or series being included in the 
Huronian system. There are several in the Cambrian and in the 
Silurian, why not in the Huronian or in the Laurentian. 
That a break or local unconformity necessarily limits a system, is 
also, I think, a somewhat novel doctrine, and if difference in the litho¬ 
logical character of strata or local accidents of unconformity are to be 
so accepted, then a vast number of new systems will have to be intro¬ 
duced into the existing, recognized geological sequence, and a magnif¬ 
icent field will be opened up for the inventors of new names for old 
things ; but what advantage will thereby accrue to geology or to science 
is a problem not easy to answer. 
Ottawa, March 18th, 1889. Alfred R. C. Selwyn, 
Director of the Geol. & Nat. History Survey of Canada. 
PERSONAL AND SCIENTIFIC NEWS. 
Very striking examples of glacier action may be seen at 
a number of points on the eastern flanks of the higher ranges 
of the Sierra Nevada mountains. 
Near the Young America mine on the opposite side of the 
“ Buttes ” from Sierra City, and nestling in a valley between 
lateral spurs of the mountain range, are two small bodies of 
water that are known respectively as Upper and Lower Sardine 
lakes. Between the two lakes there is a difference of level of 
213 feet. The upper lake has a depth of 175 feet. Its lower 
margin is formed by hard, diabasic rocks that are cleft and 
seamed in various directions, but with a general tendency to 
dip toward the lake. Here are examples of glacier-planing on 
a grand scale. The strise come up out of the lake as if the 
lake bed had been scoured out by the glacier, pass over the 
rocks forming the eastern rim of the lake basin, conform to 
all sorts of inequalities of level in the surface, arch over nu¬ 
merous rocfies moutonees , descend in a series of precipitous 
ledges and pass on into the basin of the lower lake. The sides 
of the gorge-like valley are scored to a hight of a hundred 
or a hundred and fifty feet above the bottom. 
In the lateral valley next north of that occupied by the Sar¬ 
dine lakes, occur the beautiful, blue transparent sheets of 
water known as Salmon lakes. Here the same phenomena 
occur and on a scale even grander than in the preceding case. 
This valley like the preceding terminates to the west in the 
high rocky buttes that constitute the crest of the main range, 
and from which the glacier descended to scoop out the basin 
of the upper Salmon lake. The same diabasic rocks, as in 
the case of Upper Sardine lake, and dipping in the same di¬ 
rection, formed a rim over which the glacier plunged to exca- 
