56 
IOWA ACADEMY OP SCIENCES. 
the middle ledges in the Pine creek conglomerate. It is seen 
to contain three rounded boulders from eight inches to one 
foot in diameter. One of these consists of gneiss, one of mica 
schist and one of quartzite. In a collection of 100 pebbles from 
this ledge, different rocks were represented by the number of 
pebbles indicated in the following list: 
Greenstone 
White quartz 
Yellow chert 
Granite (mostly red) 
Light red orthoclase 
Coal measure rock 
Black felsite 
Quartz-biotite schist 
Faintly pinkish white quartz 
Quartz speckled with jasper. 
Red quartzite 
Hornblende rock 
Milky quartz 
Gneiss 
26 per cent 
26 “ “ 
18 “ “ 
u u 
5 “ “ 
q u u 
3 “ “ 
3 “ “ 
9 u u 
2 “ “ 
X u u 
1 “ “ 
q u u 
q u u 
The author is inclined to the opinion that this conglomerate 
in Muscatine and that exposed on Pine creek are both outliers 
of the same formation, but he has no suggestion to offer as to 
what age they really belong farther than as above stated. 
FOREST TREES OF ADAIR COUNTY, IOWA. 
BY JAMES E. GOW. 
In order to understand the forestry conditions of Adair 
county, a short description of the lay of the land and the 
nature of the soil is first necessary. The county lies along the 
crest of the “ grand divide, ” between the Mississippi and the 
Missouri, so that a line drawn along the crest of the ridge 
traverses it diagonally from northwest to southeast. The land 
is undulating enough to secure an easy natural drainage, but 
not so undulating as to be difficult of cultivation, except in a 
few isolated localities. The soil is a rich, black loam, varying 
in thickness from a few inches to ten or fifteen feet and under- 
lain by a stiff, yellow clay. Here and there, the larger streams 
may be found flowing over beds of limestone, but as a rule 
