400 The American Geologist. June, 1892 
4. Usually the striz are parallel, as much so as in glacial 
action, and commonly on surfaces dipping up stream, but occa- 
sionally upon limited areas dipping down stream, 
While these fagts may have no direct significance of practical 
value, they indirectly throw much light upon the possible origin 
of the extra-morainic drift, and of some ancient striated sur- 
faces outside of the moraines. 
REVIEW OF RECENT. GEOLOGICAL 
LITER ATU, 
Bulletin of the Geological Society of America. Proceedings of the Summer 
Meeting held at Washington, August 24and 25,1891. H. L. Farrcn inp, | 
Secretary. Vol. iii, pp. 1-152; issued March 9, 1892. 
A fine portrait of Prof. Alexander Winchell, the deceased president of 
the society, forms the frontispiece of this brochure, which contains a 
memorial sketch of him by his brother, Prof. N. H. Winchell. 
Many papers that were read at the meeting, a considerable number of 
them being by foreign geologists who attended the International Geolog- 
ical Congress, are presented, either entire or in abstract, including notes 
on a geologic map of South America, by Dr. Gustav Steinmann, of Frei- 
burg, Germany; Thermometamorphism in Igneous Rocks, by Alfred Har- 
ker, of Cambridge, England, discussing a great volcanic series of Ordo- 
vician age in the English Lake District; The Plant-bearing Deposits of 
the American Trias, by Lester F. Ward, these deposits in the Connecti- 
cut valley, in New Jersey and Pennsylvania, Virginia and Maryland, 
North Caroline, and New Mexico and Arizona, being all referred to the 
upper Keuper, near the summit of the Triassic system; Studies in Prob- 
lematic Organisms—the genus Scol?thus (with numerous figures in the 
text), by Joseph F. James, who regards these worm-burrows as valueless 
for correlations; The Tertiary iron ores of Arkansas and Texas (with a 
map), by R. A. F. Penrose, Jr., who concludes that the limonite ores as 
now found are the products of the oxidation of original iron carbonate 
and sulphide; Sandstone Dikes in northwestern Nebraska (with illustra- 
tions in the text), by Robert Hay; The Hurypterus beds of Oesel as com- 
pared with those of North America, by Dr. Friedrich Schmidt, of St. 
Petersburg, Russia; On the marine beds closing the Jurassic and open- 
ing the Cretaceous, with the History of their Fauna, by Prof. Alexis 
Pavlow, of Moscow, Russia; Quaternary Changes of Level in Scandinavia 
(with amap), by Baron Gerard de Geer, of the Geological Survey of 
Sweden (see the GEOLOGIST, Oct., 1891, p. 236); The “Black Earth” of the 
Steppes of southern Russia, by Prof. A. N. Krassnof, of Clarkow, Russia, 
a most interesting comparison of the chernozem with the black prairie 
oil of the Mississ/ppi basin; On the existence of the Dinothertum in Rou- 
