Review of Recent Geological Literature. 203 
eastern ranges of the complex Cordilleran belt, Dr. Dawson has care- 
fully examined the section along the Canadian Pacific railway in its 
passage through the intervening Selkirk mountains. In descending 
stratigraphic order, and in geographic sequence from east to west, the 
rocks are quartzites, argillites, limestone, and schists, provisionally re- 
garded as Silurian and correlated with the Halysites beds and graphto- 
lite-bearing shales of McConnell's section ; gray schists, quartzites, con- 
glomerate, and argillites, regarded as Cambro-Silurian and Cambrian, 
having a thickness of 25,000 feet in the Selkirk range, from which they 
are denominated the Selkirk series, probably equivalent to McConnell's 
Castle mountain group and the upper part of his Bow River series ; 
blackish argillite schists and phyllites, with some limestone and quartz- 
ite, about 15,000 feet, named Nisconlith series in British Columbia ; and 
gray gneissic rocks and coarse mica schists, forming the Shuswap series 
of the Arclncan age. The Selkirk and Nisconlith series are conforma- 
ble and comprise a total thickness of 40,000 feet of strata which the au- 
thor refers to the Cambrian system, not finding reason for distinguish- 
ing the lower portion by the name Algonkian adopted by Wallcott. 
Formations above the Silurian, ranging from the Devonian to the Creta- 
ceous, which enter into the composition of the neighboring parts of the 
Rocky mountains, are nowhere seen in this section of the Selkirks. 
Graphic field notes for areal geology. By Bailey Willis. Bulletin, 
G. S. A., vol. ii, pp. 177-188, with one plate ; Feb. 12, 1891. Methods 
of field observation and record employed by the U. S. Geological Survey 
in the Appalachian mountain region are here described. Plats suffi- 
ciently accurate to be used in preparing maps for publication are made 
on pages of the note-book, from measurements of distances by pacing, 
with determination of bearings by a hand compass; but when it can be 
•conveniently carried, a traverse plane-table is used, the plats being 
then on sheets of drawing paper. These graphic methods are found to 
be far more serviceable than verbal notes for the greater part of the in- 
formation to be recorded, and they tend to make keen observers. 
Annual Report of the Geological Survey of Arkansas, for 1889. Johx 
C Branner, State Geologist, vol. ii. The Geology of Crowley's Ridge, 
By R. Ellsworth Call, Little Rock, 1891, pp. 283. Eleven plates and 
a geological map of the western portion of St. Francis county, and a 
map of Crowley's ridge showing the flooded plains of adjacent streams. 
The description of the sections and of the topography and local 
geology of the ridge is by Prof. Call, who also has •• notes on the trees 
of the ridge" and a description of a new pelecypod mollusk from the 
Tertiary (Mytilus hamatoides). 
Prof. R. D. Salisbury contributes a chapter on "the relationship of 
the Pleistocene to the Pre-picistocene formations of Crowley's ridge and 
adjacent areas south of the limit of glaciation;" and V. H. Knowlton 
describes ••unfortunately*" (as he says) four new species of fossil wood 
found by Prof. Call in his exploration of the region. 
