Xll PBEFAOE. 



Of the Third District— Butler, Clinton, Darke, Fayette, Franklin, Miami, Preble, 

 Warren. 



Of the Fourth District— Champaign, Logan, Shelby. 



It will be seen that the above list includes some of the richest and most populous 

 agricultural and mining counties in the State, and it would be a great injustice to their 

 inhabitants if, after paying their portion of the general expenses of the Survey and 

 for the publication of reports on other portions of the State, they were denied their 

 share of the benefits of the Survey. The matter for the third volume has been, to a 

 considerable extent, prepared since the appropriations for the salaries of the Geological 

 Corps were discontinued; much of it is, therefore, a gratuitous contribution, with 

 which the Corps should be credited when a comparison is made between the value of 

 their services and the compensation they have received. Some of the maps and other 

 illustrations of this volume are already engraved, so that the cost of its publication 

 will be something less than that of either of its predecessors ; in other words, from 

 seventy-five cents to one dollar a copy, according to the size of the edition published. 



A large amount of new palseontological material has been gathered during the last 

 year, which, with that crowded out of previous reports by the necessary limitation of 

 space and expense, would, if fully described, go far toward forming a third volume 

 on Palaeontology ; but no such volume has been had in contemplation, and it may 

 very well remain as a subject for farther legislation, when the financial condition of 

 the country shall better justify the expenditure of the money necessary for its pub- 

 lication. 



As the value of the palseontological portion of our report is still underestimated in 

 some quarters, it may not be out of place to repeat here what has been said on this 

 subject in some of our former reports, viz., that the fossils found in our rocks are not 

 mere objects for idle curiosity, but are of the highest practical importance, since 

 they, in fact, constitute the only reliable guides in the study of our sedimentary 

 rocks. The whole system of classification in modern geology is based upon them, and 

 it is not too much to say that no man can be a good geologist who has not consider- 

 able familiarity with them. Figures and descriptions of the characteristic fossils of 

 our formations will, therefore, prove of great utility to our students and teachers of 

 geology; and it is, indeed, difficult to see how they can make much progress in the 

 study of the geology of the districts in which they live without the assistance they 

 afford. It is also true that the wealth and power of any community consist quite as 

 much in the ideas in their heads as the dollars in their pockets ; and it is even prob- 

 able that the revelations which have been made through the Geological Survey, of 

 the strange and varied extinct forms of life with which our rocks are crowded, will 



