PLATE II. 
Lyriopecten interradiatus. 
Page 44. 
See Plate 82. 
Fig. 1. A small left valve. 
Fig. 2. A specimen of medium size. 
Fig. 3. The right valve belonging to the left valve, lig, 1. 
Fig. 4. The right valve of fig. 2. 
Hamilton group. Fultonham, Schoharie Co.. N. Y. 
Aviculopecten bellus. 
Page 35. 
See Plate 81. 
Fig. 5. A small left valve, X 2. 
Fig. 6. A similar left valve; X 2. 
Fig. 9. A specimen preserving both valves, showing their comparative form and relations, X 2. 
Hamilton group. Near Bellona, N. Y. 
Aviculopecten ornatus. 
Page 37. 
See Plate 3. 
Fig. 7. A small specimen preserving both valves slightly displaced, and the right one imperfect; 
showing the form and ornamentation, X 2. 
Fig. 8. A larger specimen, similar to the preceding-, but with the surface characters partially obliterated 
from maceration, X 2. 
. Hamilton group. Canandaigua lake, N. Y. 
Pterinopecten undosus. 
See Plate 82. 
Fig. 10. A small left valve, showing the great proportional length of hinge-line in the young shell. 
Hamilton group. Canandaigua lake, N. Y. 
Fig. 11. A large left valve, having very distant equal radii. 
Hamilton group. Bethany, N. Y. 
Fig. 12. A right valve, showing numerous concentric undulations. 
Hamilton group. Canandaigua lake, N. Y. 
Fig. 13. A right valve preserving- two strong undulations in the umbonal region, more subdued concentric 
lines below, and numerous fine radii. 
Corniferous limestone. Clarence Hollow, N. Y. 
Fig. 14. A right valve preserving a portion of the test on the upper anterior side and anterior ear. 
Hamilton group. Canandaigua lake, N. Y. 
Fig. 15. A characteristic right valve. 
Fig. 16. A large right valve, showing numerous concentric undulations. 
Hamilton group. Canandaigua lake, N. Y. 
Fig. 17. A small specimen preserving both valves and showing strong undulations. 
Hamilton group. Canandaigua lake, N. Y. 
F'igs. 18, 19. Two nearly entire large left valves. 
Hamilton group. Gleneseo, Livingston Co., N. Y. 
