156 Scientific Intelligence. 
dence goes it appears in Minnesota to graduate into this over- 
lying seaiongn conformably ;” that the overlying Nos. 2 and 3, 
which consist of horizontal light-colored siliceous sandstones with 
and others), show a relation in age to the Gnobee group, thoug 
cautiously assign ned to the Potsdam period by Hall. Professor 
Winchell is sore disposed to consider the St. Croix sandstone of 
the age of the Quebec group. [At present it seems probable that 
the Quebec group in the east will ultimately become divide 
between the Calciferous and Chaz azy.| The red sandstone forma- 
tion of Keweenaw is stated to be “locally changed to gneiss, 
syenyte, and ne rd red omar as well as interbedded with 
veins through the trap and the associated feldspar rock. 
feldspar masses are geologically from the same rock as the Rice 
Point gabbro, and both are the real of copious, ~ perhaps one 
of the earliest, aeucsue outflows of the Cupriferou 
The Report also contains descriptions and figures s of some fresh- 
water at nd other Crustaceans of Minnesota, by ©. 
C. Her ecies of Decapods are mentioned as occur- 
ring in the rivers of the State, Cambarus virilis Hagen, and the 
species, here first Waaniber and named, C. signifer. 
oded Lake Winnip n the prefatory “summary state- 
ment” of the Report, a aie th is given of the present views of Mr. 
Warren Upham with regard to flooded Lake Winnipeg, to which, 
as stated on page 433 of the last volume of this Journal, he has 
given (unfortu pees De think) the name Lake Agassiz. Mr. 
Upham makes the to have covered not merely the Red River 
irie Fe ion of leas (which bears ts goto ce of lacustrine condi- 
tions), as st by General Warren and others, but to have 
Red River Valley at St. Vincent 450 feet, and Lake Winnipeg 
about 600 feet.” The evidence referred to”as supporting this con- 
clusion consists in “beach lines,” of which there are three. The 
evidence that these supposed beach lines were of lacustrine origin 
and not fluvial is not given in this brief summa 
In explanation of the conditions of water-] nk it is stated that 
the beaches “have been ascribed to the operation of the glacial 
period in the epoch of its decline, when the ice still existed to the 
