State of Illinois, Department of Registration and Education.

Geological Survey had the valued services of America's dean of Carbonifer-ous paleobotany, Dr. David White, in a general reconnaissance of the Upper Coal Measures, now precisely referred to as the Pennsylvanian system. Previous to t h a t time but little work had been done, chiefly by Leo Lesquereux from collections by A. H. Worthen and associates. White's work led to a general correlation of the strata of the Illinois coal field with the eastern field, and to a division of the Pennsylvanian system into three series: the Pottsville (lowest), the Carbondale, and the McLeansboro. I n 1921, in connection with an intensive study of the coal resources of Illinois, the State Geological Survey undertook a program of a more detailed study of the plant forms found in strata associated with the coal beds, fully realizing that the facts to be uncovered by such an investigation would likely be of inestimable value to a proper correlation of the coal beds in different parts of our State and to our knowledge of their extent and relationships. The work is being conducted by Dr. and has already reached an advanced stage. The study is far-reaching in its relations t o the functions of the Geological Survey, to the proper identification of coal beds which the Survey uses in determining the existence of favorable structures for the commercial occurrence of oil and gas, to the estimates made of the State's coal resources, to the scientific contributions which the Survey is in position to make on both the character of the vegetation, climatic environment , and physiographic conditions of the Pennsylvanian period, and on the life history of the plant kingdom, and finally, with unneglected attention , to providing secondary schools and colleges of the State with desirable educational material. I t is designed eventually to publish a comprehensive monograph on the flora of the Pennsylvanian system of Illinois, properly illustrated and containing descriptions of both old and new species, and the conclusions to be drawn regarding coal correlations. T h e field, however, is very extensive , and, in order that advantage may be taken of data obtained in the course of the study, short bulletins covering sub-units of the State will be issued. The present bulletin is an account of the Pennsylvanian flora of northern Illinois, marking the completion of the work of one of the sub-units. Its treatment is feasibly popular, …