4 LETTER FROM THE AUTHOR. 



Major Wm. J. Davis, Profs. Wm. J. McConathy and J. T. Gaines and Dr. 

 James Knapp, of Louisville, Ky., Prof. A. C. Goodwin, of Charlestown, Messrs. 

 Orlando Hobbs, Henry Peters and Mr. Fogg, of Jeffersonville, Indiana. These 

 gentlemen have rendered me all the assistance I desired or needed, for which 

 I here express my thanks. To Major Wm. J. Davis, the author of " Ken- 

 tucky Fossil Corals," I am especially indebted for much valuable information 

 given me, while on our numerous collecting trips, and during the preparation 

 of this work. It has pained me to see the valuable collection of the late Dr. 

 James Knapp, from which Prof. Hall received most of his Ohio Falls speci- 

 mens, leave our State. Though in corals it was greatly inferior to the cabinet 

 of Major Wm. J. Davis, and in shells not equal to my own, it contained some 

 very rare specimens which it may be impossible to replace. 



Our shells have generally retained their original form, not having suifered 

 from compression or distortion, as is the case with so many fossils from other 

 localities, and their silicification has prevented all wear and rubbing after sepa- 

 ration from their matrix, while, on the other hand, their changing into horn- 

 stone has, in many instances, obliterated the original fine surface-markings, for 

 the study and description of which we have to acquire material from other 

 localities. 



The descriptions of fossils I have prefaced by a short article on geology and 

 palaeontology in general, containing information indispensable to any one who 

 wishes to gain an understanding of the fossil remains of the fauna and flora 

 of former ages. In preparing said article, I have made extensive use of the 

 works of Dana, Lyell and others. 



Hoping that this monograph will meet with your approval, and that it may 

 be of service to the students of geology, in spite of its many shortcomings, 

 which, knowing your kind disposition, I feel assured you will overlook or 

 excuse, I express here to you, dear sir, my many thanks for your kind con- 

 sideration and indulgence, and remain 



Very respectfully, your obedient servant, 



HENRY NETTELROTH. 



LOUISVILLE, 1887. 



