PLATE XXII-Continue.l. 
Fig-. 18. A large ijygidiuin. 
Fig. 19. Profile of the same. 
Schoharie grit. Pendleton, Indiana. 
Proetus crassimarginatus. 
Page 99. ifi 
See Plates 20 and 25. 
Fig. 20. A small pygidium, retaining the thickened border. 
Schoharie grit. Near Clarksville, Albany county. 
Fig. 21. A pygidium, preserved as a cast of the intej-nal surface and showing the annulations with unusual 
distinctness. 
Schoharie grit. Near Clarksville, Albany county. 
Fig. 22. A fragmentary individual of large size, preserved as a cast of the internal surface. 
Upper Helderbei'g limestones. Cayuga, Province of Ontario^,. 
Fig. 23. Profile view of a small pygidium, showing an abnormal prominence of the extremity of the axis. 
Corniferous limestone. Falls of the Ohio. 
Fig. 24. Pi’ofile view of an enrolled individual, from which most of the crust has been removed. 
Fig. 25. Anterior view of the same specimen, showing the internal casts of the glabellar fui-rows, through 
the pai-tially removed crust. 
Corniferous limestone. Sandusky, Ohio. 
Fig. 26. A normal pygidium. d' 
Cornifei'ous limestone. Williamsville, Erie county. ■[{ 
Proetus stenopyge. 
Page 110. 
Fig. 27. A pygidium, showing the short, broad, convex and obtuse axis. Enlarged to three diameters. 
Corniferous limestone. Phelps, Ontario-county. 
Proetus olarus. 
Page 101. 
See Plate 20. 
Fig. 28. An internal cast of the glabella, showing the lateral furrows. 
Upper Helderberg limestone. De Ceioville, Province of Ontario. 
Fig. 29. An entire individual, somewhat flattened, but showing the characters of the species. 
Corniferous limestone. Lime Rock, Genesee county. 
Fig. 30. An imperfect pygidium. 
Corniferous limestone. Falls of the Ohio. 
Proetus ovifrons. 
Page 110. 
Fig. 31. An internal cast of the glabella, showing its form and convexity, the size of the basal lobes, and 
the recurved frontal border. Enlarged to three diametei’S. 
Corniferous limestone. Canandaigua, Ontario county. 
Fig. 32. A glabella, preserving the dorsal surface and showing the pustulose character of the crust. En¬ 
larged to three diameters. 
Corniferous limestone. Canandaigwa, Ontaino county. 
Proetus microgemma. 
Page 109. 
Fig. 33. A normal pygidium, showing the characteristic ornamentation, and the broad border. Enlarged 
to two diametei-s. 
Corniferous limestone. Phelps, Ontario county. 
Fig. 34. A very small pygidium, referred with some doubt to this species. The annulations are more dis¬ 
tinct and more numerous than in the preceding specimen, a feature which may be due to a less 
advanced stage of growth. The axis'is covered with fine pustules, which are not represented 
in the figure. The relatively large size of the axial nodes give an appearance of angularity 
to the annulations. Enlarged to six diameters. 
Corniferous limestone. Canandaigua, Ontario county. 
Phillipsia, sp. ? 
Fig. 35. The pygidium. A siiecimen from which a portion of the crust has been removed. 
Lower Carboniferous limestone. Near Grand Rapids, Michigan. 
