620 GEOLOGY OF OHIO. 



Supplerrpei^t. 



ON THE VENTRAL ARMOR OF DINICHTHYS. 

 By Prof. Albert A. Wright, Oberlin, Ohio. 



PLATE VII. 



Owing to the isolated and imperfect condition in which most of the 

 remains of Dinichthys are found, it has not yet been possible to give a 

 complete account of the skeleton and armor of the fish, or to assign 

 the plates to their correct positions. Many unfigured and undescribed 

 bones in the collections are awaiting the hitherto undiscovered evidence 

 as to their precise position and relationships. From time to time, how- 

 ever, advances are made bj T the finding of more perfectly preserved ma- 

 terials, either in their correct original relations or in those that are very 

 suggestive; and I am now fortunate enough to be able to add something 

 to our previous knowledge of the ventral armor of Dinichthys from 

 specimens in the museum of Oberlin college. 



The facts which I have to offer are not precisely an addition to 

 knowledge in a region where nothing was known before; but principally 

 a rearrangement of some of the isolated elements of the armor, which 

 elements have already been figured and described. 



In order that these facts may stand in a clear light, it will be 

 necessary to refer to the original account of the ventral armor given by 

 Dr. Newdoerry in the Paleontology of Ohio* and to his supplementary 

 account in the Monograph upon the paleozoic fishes of North Americaf 



These accounts give an instructive history of the progress of dis- 

 covery in this field, and of the changes which it has already been 

 necessary to make in the arrangement of the plates. 



*Ohio Geo. Survey, Paleontology Vol. II. 

 tU. S. Geol. Survey, Monographs, Vol. XVIL 



