291 
to show that the Crawfordsville crinoid beds, which have been regarded 
as belonging to the Keokuk, are the statigraphical equivalents of the 
Knobstone strata farther south. 
The accompanying map shows the area covered by the Knobstone 
group, north of Morgan County, as that area is given on Gorby’s geo- 
logical map of 1893. It shows also (approximately) the area in and north 
of Putnam County as the field work of 1897 indicates it to be. 
It will be noticed that (as worked out by the University Sais of 
1897) no Knobstone is represented as occurring north of Montgomery 
County, while by far the larger part of that county is underlain by it. 
Small isolated areas of the Knobstone may exist north of Montgomery 
County, but these will in all probability be found to be only outliers. 
The limits of the area, as changed from Gorby’s map of 1893, are 
only approximate. The whole region being covered over by glacial drift, 
except in the deepest creek valleys, makes it necessary to trace the con- 
tacts largely by well sections. It is consequently impossible to trace them 
more than approximately. 
Some InpranaA Mruprews.* By M. A. BRANNON. 
Four years ago a paper on ‘“‘Mildews of Indiana’’ was presented to 
you by Mr. J. N. Rose, of Wabash College. His was the first step toward 
determining the various species of Indiana mildews. The few species, 
and their hosts, named in this paper are the second attempt, I believe, in 
this State in the direction of determining these interesting parasites, 
which are everywhere abundant. 
To Rose’s list, containing the names of eleven species and twenty-nine 
hosts, are added several hosts for some of the species mentioned by him, 
also nine species and ten hosts not found in his list. 
Bessey’s ‘‘Erysiphe of the United States; Cook’s ““Hand-Book of Brit- 
ish Fungi;”’ Bull. of the Ill. State Laboratory of Nat. History, Vol. II., and 
Rose’s ‘‘Mildews of Indiana’ were the guides used in determining and 
describing the following species. 
Spherotheca Castagnei Léy. 
*Paper read before the Indiana Academy of Science, 1889, and heretofore unpublished. 
