PREFACE. Vll 



found in the excavation of the Ohio Canal, at Nashport, and it was 

 brought to the notice of the scientific world by the late Col. J. W. Foster, 

 when connected with the first geological survey of the State. Perhaps 

 no other of our extinct animals has excited a deeper interest than this 

 one, and nothing that could be published in our palaontological reports 

 would be read with greater avidity than any new information in regard 

 to Castoroides. 



4. Our reports would also be glaringly incomplete if they should fail 

 to contain some notice of the elephant, the mastodon, the horse, the 

 musk-ox, the reindeer, the bison, true oxen, and other large mammals, 

 the remains of which have been found in our State. Some of these re- 

 mains have never been seen by any comparative anatomist, and none of 

 them have been carefully studied. Prof. Marsh has consented to exam- 

 ine this material — which, though scattered and rapidly disappearing, 

 is still considerable in quantity — and we may confidently anticipate that 

 in his hands it will form the basis of a very interesting chapter in our 

 ancient history. 



5. A considerable number of new species of invertebrate fossils still 

 remain in our hands for description. These are chiefly MoUusks from 

 the various formations of our geological scale. Many of them have been 

 already studied, and it only remains to have descriptions and drawings 

 of them made to bring the Palaeontology of Ohio in all departments up 

 to date. It is hoped that this material also will form part of Volume III. 



Among the special reports which form the present volume, it will be 

 seen there is one by Prof. H. A. Nicholson, now of the University of St. 

 Andrews, Scotland, on our Silurian and Devonian Corals. It is only an 

 act of justice to state that this report was written and the drawings 

 which illustrate it were made by Prof. Nicholson himself on the eve of 

 his departure for Europe, when his time was peculiarly precious to him, 

 and that both report '.and drawings were furnished without compensation. 



The plates, which form so important a part of this volume, were litho- 

 graphed by Messrs. T. Sinclair & Son, of Philadelphia, and Strobridge & 

 Co., of Cincinnati — the MoUusks, Crustaceans, and Salamanders by the 



