58 The American Geologist. July, 1900 
dependently in dififerent regions, under similar environment, and that 
they spread with great rapidity over northern lands. He is led to this 
idea by the essential contemporaneity of floras in nearly all the coal 
basins of the northern hemisphere, along with their wonderful re- 
semblance in composition, or homogeneity, and especially the par- 
allelism of appearance and disappearance of types, and the uniformity 
of their sequence. h. l. f. 
Report on Fossil Plants from the Mc A tester Coal Field, Indi- 
an Territory , Collected by Messrs. Taff and Richardsoti in i8gy. 
By David White, U. S. Geol. Survey, Nineteenth Annual Report, 
i8q7-q8, Part III, Economic Geology, pp. 457-536. 
As this paper is the first description of coal plants from the south- 
western margin of the Carboniferous basin, it has both biological and 
geological interest. The quantity of material is not inconsiderable, 
seventy-five plant forms being listed in the correlation tables. Seven 
new species and two varieties are described, mostly ferns, and the en- 
tire flora is described and discussed in the thorough and scholarly 
manner usual with the. author. 
The plants are from three widely separated horizons and conse- 
quently show decided biological dififerences, only two ferns being com- 
mon to all three horizons. The highest horizon is a cut on the Missou- 
ri, Kansas and Texas railroad, one-half mile south of McAlester and 
about 2,000 feet higher stratigraphically than the McAlester coal, the 
middle horizon. The lowest horizon is 1,500 feet below the McAlester 
coal and is supposed to be identical with the Grady coal at Hart- 
shorne. 
Having such great vertical range and great botanical variation, 
a comparison of these floras with those of other and distant localities 
of the bituminous coal fields would be interesting and useful. Unfortu- 
nately there is very little available information for such comparison 
except from either the lower productive measures 01 the Permian. 
Over great areas of the bituminous regions, no collections whatever 
have been made and the few made are so incomplete as to have little 
correlation value. 
The author regards the highest stage as much earlier than the Per- 
mian or upper barren measures; the middle, McAlester, stage as lying 
in the Upper Coal Measures (Missourian) of the Western Interior 
basin, and probably older than the Pittsburg coal; and the lowest 
stage, the Grady coal, as near the Mazon creek or Cannelton horizon 
of the lower productive Coal Measures (Alleghany series) and prob- 
ably in the lower half. For the great thickness^f these Coal Measures 
strata the author finds a parallel only in the Kanawha series of West 
Virginia for the lower half, and in the Joggins section of Nova Scotia 
for the remarkable dilation of the upper part. 
Comparing the floras with European coal floras, the author confi- 
dently correlates the Grady coal flora with the Middle or perhaps the 
Lower Coal Measures of Great Britain, and with the Valenciennes 
