OF 
Volume XIX Articles 1-4 
Foreword. By President Clark W. Chamberlain 
1. Echinodermata of the Brassfield (Silurian) formation of Ohio. 
By Aug. F. Foerste 3 
2. America’s Advance in Potash Production. By W. C. Ebaugh... 33 
3. The Use of Outline Charts in Teaching Vertebrate Paleontology. 
By Maurice G. Mehl 47 
4. Some Factors in the Geographic Distribution of Petroleum. By 
Maurice G. Mehl 55 
GRANVILLE, OHIO, APRIL, 1919 
Denison University Bulletins University Series Vol. XIX, No. 3 
The University Bulletins are issued bi-monthly, and are entered at the Postoffice 
at Granville as mail matter of the second class. 
