PLATE VI— Continued. 

 Fig. 26. A fragment of a cephalon, showing the hypostoma in place. 



Schoharie grit. Schoharie, Schoharie county. 

 Fig. 27. A cast of the lower surface of :i pygidium, showing traces of the grooves upon the pleural aimu- 

 lations. 



Schoharie grit. Near Clwrksville, Albany comity. 

 Pig. 28. A rust df a larger pygidium, showing the simple pleural annulations ; their usual appearance in 

 an impression of the lower surface. 



Upper Helderberg limestone. SchiMz's farm, near Clarence, Erie comity. 

 Fig. 29. A very large pygidium in the same condition of preservation. 

 Schoharie grit. Schoharie, Schoharie county. 



Phacops RANA ? 

 Fig. 14. Dorsal view of a specimen retaining the parts in juxtaposition. The head is slightly displaced 



and somewhat imperfect. 

 Fig. 15. Profile of the same, showing the elevation of the body. 

 Upper Helderberg limestone. Ohio. 



