Devonian Era in the Ohio Basin. — Clay pole. 15 
THE DEVONIAN ERA IN THE OHIO BASIN. 
By Edward Claypole. 
Part I. 
PLATES IV-X. 
This paper, in a different and more complete form, received the Walker prize 
in 1 895. It has been thought best, after the most careful consideration, not to 
longer delay publication, but to make such revision and abridgement as would 
suit it to the magazine in which, with peculiar fitness, it now appears. The 
original paper in the form of a monograph, consisted of four chapters, viz.: 
Siluria, Devonia, Palaeontology of Devonia in Appalachia and a Sum- 
mary, together with a Geological Forecast. Of these, Devonia is here 
presented with certain necessary changes, while the Palaeontology is but 
slightly altered and two other parts are entirely omitted. 
In this work we hare been guided by the wise counsel of Dr. Theodore B. 
Comstock, who has given unsparingly of his time and thought. For this aid 
we wish to express our deepest gratitude. Constant effort was made to avoid 
changes, but when these were necessary, the original style and form were 
scrupulously retained. 
Pasadena, California, Edith J. Claypole. 
June, 1903. Agnes AI. Claypole. 
BIBLIOGRAPHY. 
[The list given below does not profess to be a complete index to 
the literature of the Devonian era in the Ohio basin but contains some 
additional works while including those quoted in the essay.] 
1. Proceedings of the American Philosophical Society, 1884. "On 
the Structure of the Skull in the Elasmobranch genus Didy- 
modus." E. D. Cope. 
2. Contributions from the Geological Department of Columbia Col- 
lege. No. XX. "Contributions to the Morphology of Clado- 
selache or Cladodus." Bashford Dean. 
3. "Geological position of the Catskill Group." C. S. Prosser. Am. 
Geologist, June, 1891. 
4. "Contributions to American Paleontology." Cincinnati. E. 0. 
Ulrich. 
5. "Bryozoans of the Upper Helderberg. and Hamilton Groups." 
James Hall. 
6. Report of Progress of Second Geological Survey of Pennsylvania. 
"Ceratiocaridse from the Chemung and Waverly Groups." C. E. 
Beecher. 
7. Geological Survey of Alabama and Bulletins. Eugene A. Smith. 
8. Geological Survey of Kentucky. N. S. Shaler. 
9. Geological Survey of Ohio. Newberry and Orton. 
10. Quarterly Journal of the Geological Society of London, 1884 and 
1892. "On Palseaspis." E. W. Claypole. 
