306 Scientific Intelligence. 
Co., the following fossils—identified by R. P. Whitfield: Zeio- 
rh ynehus a icostata Hall, Chonetes lepida Hall, 7% qntacuiites 
Jissurela Hall, a fragment of a Cardiola near C. radia The 
«RE a is a Genesee shale dee ak the Tentaculites is found 
as well in the Marcellus and Hamilton beds; the Chonetes be- 
longs to the Hamilton and possibly also to the Genesee ; while 
z e 
white porcelain cig cupying “ ae in the 
Carboniferous rocks of Pope County, has been long known under 
the n of rolconda clay. In Lawrence County the clay ae 
is five to six feet thick fonethud pure white) and has a wide ex- 
tent. It is underlaid by a bed of limonite five feet and less in 
ad It lies beneath the Millstone grit and seems to corre- 
spond to an epES member af the Archimedes cepa a 
ag 
unctuous feel. It is called Indianaite or Mr. The kaolin 
contains masses of allophane of a Spa ae “emerald-green 
color, one specimen of which afforded Dr. J. Lawrence Smith: 
Silica 20 per cent, alumina 40, water 40. All degrees of grada- 
tion exist between the allophane and kaolin. 
Analysis of the ripe atforded— 
Fe Mn Ca, Mg H 
Var. A rs 90 40°34 en oe siete 13°26 
— B 47°05 37°14 tr. 03 03 15°55 
C 47°13 36°76 tr. —- “04 15°13 
ce 42°28 43°05 — tr. 14°66 
The several County Reports with ae — present much val- 
uable matter on the Qua aternary, Devoni , Carboniferous and 
Subcarboniferous rocks. Prof. Collett anes that the bo boulder 
clay of Northern Illinois has its southern limit in the northerD 
art of Brown Co., with little thickness, but in Northern Illinois 
it ae _ to 250 feet thick; and he adds some facts re spect- 
ing erosions by the waters from the melting glacier. 
sections ihustestalie the relations of the Black Shale to the other 
rocks are given by Professor Borden, whose discoveries in it are 
eae above 
e Geological and Natural History Survey of Minnesota: 
The ‘Third Annual Report, for the year 1874; by N. H. Wince- 
ELL, State Geologist. Submitted to the President of the Uni- 
versity of Minnesota, Dec. 31, 1874.—Prof, Winchell, in this 
OF Fre treats of the Geology of Freeborn and Mower Counties: 
! ounty Mr. Winchell remarks, “There is not ® 
ral exposure of the underlying rock” and \¢ hence the details 
oye its geological structure are wholly unknown.” The field is 
