PLATE XXI. 



CviMIASPIS OKNATA. 

 Page 145. 



See Plate 24. 

 Pig 1 . 1. A fragment of the cephalon, showing the characteristic border. Enlarged to three diametei 

 Hamilton group. Eighteen-miU Creek, Erie county. 



Proetus Row i. 



Page 119. 

 See Piute 23. 

 Kg. 2. Anterior view of an obliquely crushed specimen. 

 Fig. 3. Posterior view of the same. 



Hamilton group. Summit, Schoharie county. 

 Pig. 4. The original of Dr. Green's description, drawn from a east. 



Hamilton group. Otsego comity. 

 Fig. 5. An imperfect specimen, drawn from an impression of a natural mould of the dorsal surface. 



Hamilton group. ( it si go county. 

 Pig ti, A small, imperfect example, enlarged to two diameters. 



Hamilton group. Western New York. 

 Fig. 24. An entire individual, enlarged to two diameters. In the drawing- the border is made to "appear 

 too convex, and the faint lateral glabellar furrows are not represented. 

 Tully limestone. Near drill. Seneca county. 

 Fig. 25. A smaller individual enlarged to two diameters. The crust is broken awaj from the glabella, 



showing the lateral furrows very distinctly. 

 Fig. 26. Profile view of the same, showing the normal convexity. 

 Tully limestone. Near Ovid, Seneca county. 



Proetus Haldemani. 



Page 11:;. 

 See Plate 23. 

 Fig. 7. The original specimen, enlarged to two diameters. 

 Fig. 8. Profile view of the same, similarly enlarged. 

 Hamilton group. Pennsylvania. 

 Fig. St. A small pygidium, enlarged to two diameters. 



Hamilton group. (Gonia.tite limestone.) Cherry Valley, Otsego county. 



