PLATE X. 
Lyriopecten Priamus. 
Page 51. 
See Plate 82. 
Fig-. 1. A left valve, showing- the form and surface characters. The figure should also show numerous fine 
rays on the posterior ear. 
Fig-. 2. A similar left valve, showing considerable variation in the surface characters, and strong liga 
mental area with a central cartilage-pit. 
Chemung group. Franklin, Delaware Co., N. Y. 
Aviculopecten STRIATUS. 
Page 22. 
Fig. 3. A left valve ; the original of fig. 7, p. 264, Geolog. Rept. Fourth Dist. N. Y. 1843. 
Fig. 4. An enlargement of the same, showing more distinctly the characters as described. 
Chemung g-roup. Painted Post, Steuben Co., N. S. 
Lyriopecten anomi^eformis. 
Page 53. 
See Plates 4 and 82. 
Fig. 5. A left valve. This specimen is more correctly represented on plate 82, fig. 2. 
Chemung- group. Chemung creek, N. Y. 
Lyriopecten tricostatus. 
Page 4S. 
See Plates 4 and 7. 
An imperfect left valve preserving a portion of the striated lig-amental area and the cartilage pit. 
Chemung group. Chemung Co., N. Y. 
A small left valve with the posterior side undeveloped from accident or natural deformity. 
Chemung group. Near Elmira, N. Y. 
A large left valve, showing the byssal notch on the anterior side and the comparative size of the 
anterior and posterior ears. The posterior ear in the specimen, shows several obscure rays 
and the ligamental area is strongly striated. 
Chemung group. Near Elmira, N. Y. 
A fragment of a large left valve preserving a more extended posterior ear than usual. The 
anterior ear is too much extended in the figure and should be represented as in fig. 8. 
A left valve with a portion broken away, showing what appears to be the right valve beneath. 
The stronger radii should be continuous over the interval occupied by the other valve, and 
the finer lines on that valve should be of the same character as on the left valve. 
Chemung- group. Broome Co., N. Y. 
12. Two small left valves representing the form and ornamentation of the shell at this period of 
growth. 
Cheimmg group. Chemung Co., N. Y. 
Fig. 6. 
Fig. 7. 
Fig. 8. 
Fig. 9. 
Fig. 10. 
Figs. 11, 
