364 The American Naturalist. April, 
strata standing vertically, with a strike east,—a discordance of stratifi- 
cation with the Huronian beds, which dip at an angle of 20°, with a 
strike mostly northeast and southwest. He is convinced of their iden- 
tity with the vertical strata in Minnesota, and the Kewatin system, 
Also, they are the prolongation of the ‘“ Lower Slate Conglomerate” 
of the Thessalon valley. (dm. Geol., Dec., 1890). Charles Proiser 
has examined the records of drilling in western central New York, 
and from these well sections has compiled a general section giving the 
_thickness of the different geological formations, together with the total 
thickness of the series from the lowest Coal Measures down to the 
Archean. The results show that the thickness of these formations has 
been greatly underestimated. (Am. Geol, Oct., 1890. )——Messts. 
H. R. Geiger and Arthur Keith have worked out the structure of the 
Blue Ridge near Harper’s F erry, and refer the disputed sandstones to 
the Upper Silurian. (Bull. Am. Geol. Soc., Vol. IIL., pp. 155-164.) 
The recent studies of C. Willard Hayes in the Southern Appa- 
lachians have shown a modification of the well-recognized types 
unsymmetrical fold and the reversed fault, namely, broad overthrust 
Faults which, as developed in Northwestern Georgia, are comparable 
in magnitude with those of the Scottish Highlands and the Rocky 
Mountains, as described by Geikie and McConnell. (Bull. Am. Geol. 
Soc., Vol. II., pp. 141-154). An Ordovician chert has been found in 
the Llandeilo-Caradoc rocks of South Scotland, which is considered by 
G. J. Hinde to be due to an accumulation of the tests of Radiolaria. The 
beds of fine-grained red and green mudstones associated with the chert 
favor the view of a deep-sea origin. Mr. Hinde has described twenty- 
five new species from this rock, referable to fifteen genera, for the most | 
Part also new. (Ann. and Mag. Nat. Hist., July, 1890.)——Mr. A. 
Winslow states that the flexing of the strata in the coal region of at 
estern Arkansas is essentially Appalachian. A study of the various 
flexures reveals many features which call for compression and lat oo 
movement, and this movement was from the south. The date H 
elevation must have been post-Carboniferous and pre-Mesozoic. (Bull. 
Am. Geol. Soc., Vol. II., pp. 225-242.)——According to Eugene 4. 
Smith, the Alabama Coal Measures have an aggregate thickness 
5:525 feet. They are characterized by the small amount of sulphur, 
y an almost entire absence of limestone, and by having 4 conglom- Ss 
erate at the top of the series. (Alabama Geol. Survey, 1890. pik om 
A. C. Seward agrees with Dr. Stur that Asterophyllites and Spheno- — 
phyllum are parts of the same plant. This idea was first suggested 1 
1853 by Newberry, who stated at that time that the difference betwee? 
