PLATE VII. 



AVICULOPECTEN DUPLICATUS. 



Page 17. 

 See Plate 81. 

 Fig. 1. An imperfect right valve. 



Chemung group. Hobbieville. N. T. 

 Fig. 2. A left valve, which shows the prevailing charaoter of the species in ha\-ing the anterior side longer • 

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

 Chemung gi-oup. PHUpsTjurg, Alleghany Co., iV. Y. 

 Fig. 3. A somewhat larger left valve. 



Chemung gi-oup. Mockuille, Alleghany Co., N. T. 

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



Chemung gi-oup. Rockmlle, iV. T. 

 Fig. 5. Aleftvalve. The outline of the figure is somewhat too high and too short, and liears an niniatural 

 resemblance to the succeeding species. 



Chemung group. Rockville. N. T. 

 Fi"-. 6. A right valve. The figure represents the body too .short, the sti-i;e too sh.arp .and the beak too 



obtuse. 



Chemung group. East Randolph, N. T. 



Fig. 7. A small left valve. 



Chemung grouji. Jinckville. iV. Y. 



AviCULOPECTEN RUG^STRIATUS. 

 Page 15. 

 See Plate 81. 

 Fi". 8. A small left valve nearly entii-e, showing the usual form of tlie s]>i>cies. , 



Chemung group. PhiUpslmrg, N. Y. 

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

 Fig. 10. An enlargement of the surface, showing the character of the ornanicnlatioii. 

 Fig. 11. A nearly entire right valve. 



Chemung group. Rockmlle, jX. Y. 



AviCULOPECTEN C.4NCELLATUS. 



Page IS. 

 Fig. 12. A right valve, showing the usual form and proportions. 



Chemung group. Phllipshnrg, N. Y. 

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



Chemung group. Cotiewarigo, Cattaraugus Co., N. Y. 

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

 Fig. 16. The interior impression of a right valve, with radii partially pnisevved. 



Chemung group. Westfield, N. Y. 

 Fi"-. 17. An enlargement of a small right valve to two diameters. 



Chemung grou]3. Conmmngo, N. Y. 

 Figs. 18, 19. A right valve, natural size and enlarged. The specimen is somewhat distorted from pressui'e, 

 and does not represent the normal form of the shell. 



Chemung group. Rockville. N. Y. 



AviCULOPECTEN ItYS. 

 Page 20. 

 Fig. 13. The right \alve described. 



Chennmg group. Conewango, N. Y. 



AviCULOPECTEN SQUAMA. 

 Page 27. 

 Fig. 20. A ritrht valve enlarged to two diameters, showing the form, ears and surface markings. 

 Chenuing group. Philipshurg, N. Y. 



