VOLUME 19 
Articles 1-4, pp. 1-64 ; April, 1919 $0.75 
Echinodermata of the Brassfield (Silurian) formation of Ohio ; Aug. F. Foerste. 30 pp., 7 plates. 
America’s advance in potash production ; W. C. Ebaugh. 14 pp., 2 figs. 
The use of outline charts in teaching vertebrate paleontology; Maurice G. Mehl. 8 pp., 1 fig., 
4 plates. 
Some factors in the geographic distribution of petroleum ; Maurice G. Mehl. 0 pp„ 2 plates. 
Articles 5-8, pp. 65-146 ; September, 1919 $0.75 
Notes on Isotelus, Achrolichas, Calymene and Encrinurus ; Aug. F. Foerste. 18 pp., 6 plates. 
Some suggested experiments for the graphic recording of speech vibrations ; Rpbert James Kel- 
logg. 14 pp.; 6 figs. 
The manipulation of the telescopic alidade in geologic mapping ; Kirtley F. Mather. 46' pp., 13 figs. 
The importance of drainage area in estimating the possibilities of petroleum ' production from 
an anticlinal structure; Kirtley F. Mather and Maurice G. Mehl. 4 pp., 2 plates. 
Articles 9-12, pp. 147-224; May, 1920 $0.75 
Psychological factors in vocational guidance; Thomas A. Lewis. 10 pp. 
The \ise of models in the interpretation of data for determining the structure of bMded rocks ; 
Maurice G. Mehl. 12 pp., 6 figs., 2 plates. 
Some suggestions for indicating drilling operations ; Maurice G. Mehl. 6 pp., 3 figs. 
The Kimmswick and Plattin limestones of Northeastern Missouri ; Aug. F. Foerste. 50 pp., 
3 plates. 
Articles 13-16, pp. 225-329; September, 1921 : $0.75 
Education for scholarship ; William E. Castle., * ’Q pp. 
The cytology of the sea-side earwig, Anisolabis maritima Bon., part 1 ; Sidney I. Kornhauser. 
13 pp., 3 plates. 
Notes on Arctic Ordovician and Silurian cephalopods ; Aug. F. Foerste. 60 pp., 9 plates. 
Revolution vs. evolution : the paleontologist renders his verdict ; Kirtley F. Mather. 18 pp. 
VOLUME 20 
Articles 1-3, pp. 1-36 ; November, 1922 $0.50 
A review of the biology of sex-determination ; Sidney I. Kornhauser. 21 pp., 8 figs. 
The Meander patterns of Rios Secure and Mamore, Eastern Bolivia; Kirtley F. Mather. 7 pp., 
2 figs. 
Primitive musical instruments of the Denison Collection ; Karl K[. Eschman. 10 pp., 3 plates. 
Articles 4-8, pp. 37-186; June, 1923 $0.75 
Notes on Medinan, Niagaran, and Chester fossils ; Aug. F. Foerste. 84 pp., 13 plates. 
The egg and larva of Hesperia juba Bdv. ; A. W. Lindsey. 7 pp., 1 plate. 
The occultation of Venus by the Moon on January 13, 1923 ; P. Fiefeld. 4 pp., 1 plate. 
A botanical survey of the campus of Denison University; Dwight Munson Moore. 23 pp., 7 figs., 
8 plates. 
The underground migration of oil and gas ; Kirtley F. Mather. 31 pp., 1 fig. 
NOTEzIn accordance with a ruling of the iM>stal autliorities it has becom€i 
necessary to change the name of this publication from ^'BULLETIN” to ^'JOURNAL** 
of the SCIENTIFIC LABORATORIES of DENISON UNIVERSITY. 
