Fig. 1. 
Fig. 
2. 
Fig. 
3. 
Fig. 
4. 
Fig. 
5. 
Fig. 
6. 
Fig. 
24. 
Fig. 
25. 
Fig. 
26. 
Fig. 7. 
Fig. 8. 
Fig. 9. 
PLATE XXL 
Cyphaspis oknata. 
Page 145. ' - • ' ‘ 
See Plate 24. 
A fragment of the cephalon, showing the characteristic bordei-. Enlarged to three diametei's. 
Hamilton group. EigMeen-mile Creek, Erie county. 
Proetus Kowi. 
Page 119. 
See Plate 23. 
Antei’ior view of an obliquely crushed specimen. 
Posterior vdew of the same. 
Hamilton group. Summit, Schoharie county. 
The original of Dr. Green’s description, drawn from a cast. 
Hamilton group. Otsego couJity. 
An imperfect specimen, drawn from an impression of a natural mould of the dorsal su7-face. 
Hamilton group. Otsego county. 
A small, imperfect example, enlarged to two diameters. 
Hamilton group. Western New York. 
An entire individual, enlarged to two diameters. In the drawing the bordei- is made to appear 
too convex, and the faint latei-al glabellar furrows are not represented. 
Tully limestone. Near Ovid, Seneca county. 
A smallei- individual enlarged to two diameters. The crust is broken away from the glabella, 
showing the lateral furrows very distinctly. 
Profile view of the same, showing the normal convexity. 
Tully limestone. Near Ovid, Seneca county. 
Proetus Haldemani. 
Page 113. 
See Plate 23. 
The original specimen, enlarged to two diameters. 
Profile view of the same, similarly enlai-ged. 
Hamilton group. Pennsylvania. 
A small pygidium, enlarged to two diameters. 
Hamilton group. (Goniatite limestone.) Cherry Valley, Otsego county. 
