Since 1927 the writer has been engaged in a study of the stratigraphy, structure, and paleontology of Mount Jura, California, undoubtedly the finest Jurassic section in North America. Elucidation of the stratigraphy has been made extremely difficult by the complexity of the geologic structure of the mountain. The work is now complete, however, and a monograph on the geology and paleontology is being written. Since it may be some years before that monograph can be issued, this article is published as an advance summary of results.
The writer is under deep obligations to the University of California and to the National Research Council for generous financial aid, without which the drain on his private funds would have been unbearably heavy. Dr. T. W. Stanton and, later, Dr. J. B. Reeside, have been very kind in extending the hospitality and technical services of the United States National Museum and . . .