40 PALEONTOLOGY OF OHIO. 



mens sliow that it was prodneed to a moderately acute, flattened point. 

 This narrow end was beautifully denticulated, was tuberculated on both 

 sides, and evidently projected from the body or head as a defensive spine. 



Fig. 2. represents the inside of a scale-like scute, which was probably 

 attached by its entire under surface. At the narrow end. the bone is 

 removed, revealing the impressions of the tuberculation of the outer sur- 

 face. 



The original of Fig. 3 is a small scute corresponding to la; though 

 drawn out to an acute point it was not a spine. 



Figs. 4, 5, 6 represent broader and narrower spine-like scutes, which I 

 have reason to believe belonged to the same species with the scutes from 

 which Figs. 1, 2, and 3 are drawn. Specimens of intermediate charactei- 

 seem to unite them all together. 



Formation and locality : Corniferous limestone, Sandusky, Kelly Island, Marble Head 

 and Delaware, Ohio. 



