PLATE VII. 



AVICULOPECTEN DUPLIOATUS. 



Page 17. 

 See Plate 81. 

 Fig 1 . 1. An imperfect right valve. 



Chemung group. HobbieviUe, N. Y. 

 Fig. L». A. left valve, which, shows the prevailing character of the species in having the anterior side longer 

 and more extended than the posterior. The original of the species. 



Chemung group. /",<"' . .\ )\ 



Fig. 3. A somewhat larger left valve. 



Chemung group. RockviUe, AllegJumy Co., ST. 7. 

 Fig. 4. The surface of a specimen enlarged to three diameters. 



Chemung group. Rockoille, X. Y. 

 Fig. 5. A left \ alve. The outline of the figure is somewhat too high and too short, and bears an unnatural 

 resemblance to the succeeding species. 



Chemung group. Rockoille, .V. Y. 

 Fig. 6. Aright valve. The figure represents the body too short, the stria too sharp and the beak ton 

 obtuse. 



Chemung group. East Randolph, A". 1". 

 Fig. 7. A small left valve. 



Chemung group. Rockoille, N. Y. 



AVICULOPECTEN RUG-ffiSTRIATUS. 



l*age 15. 



See Plate 81. 



Fig. 8. A small left valve nearly entire, showing the usual form of the species. 



Chemung group. Philipsburg, ZV. Y. 

 Fig. 9. A larger left valve of similar character to the preceding. 



Fig. ID. An enlargement of the surface, showing the character of tl rnamentation. 



Fig. 11. A nearly entire right valve. 



Chemung group. RockviUe, N. Y. 



AVICULOPECTEN CAXCELLATUS. 

 Page is. 

 Fig. 1 J. A right valve, showing the usual form and proportions. 



Chemung group. Philipsburg. X. Y. 

 Fig. 14. A right valve preserving the ears and surface markings in a very perfect condition. 



Chemung group. Conewango, Cattaraugus Co., TV. Y. 

 Fig. 15. An enlargement of the preceding specimen to two diameters. 

 Fig. 10. The interior impression of a right valve, with radii partiallj preserved. 



Chemung group. Westfield, X. 1". 

 Fig. 17. An enlargement of a small right valve to two diameters. 



Chemung group. Conewango, N. Y. 

 Fig's. IS. 19. A right valve, natural size and enlarged. The specimen is somewhat distorted from pressure, 

 and does aot represent the normal form of the shell. 

 Chemung group. Ro . X 1". 



AVICULOPECTEN Ity*. 

 Page 20. 

 Fig. 13. The right valve described. 



Chemung group. . .V. 1". 



AVICULOPECTEN SQUAMA. 

 Page 27. 

 Fig. 20. A right valve enlarged to two diameters, showing the form, •■ais and surface mai-kin \ 

 Chemung group. Philipsburg, X. Y. 



