PLATE III. 



AVICULOPECTEN IdAS. 

 Page 13. 



See Plate 24. 

 Fig. 1. A small right valve. 



Hamilton group. Fultoiiham. Schoharie Cu., N. F. 

 Fig. 2. A larger example of more nearly normal proportions. 



Hamilton gi-oup. Darlen, N. T. 



AviCULOPECTEN SCABRIDUS. 



Page 7. 

 Fig. 3. A young indi\'idual, apparently, of this species, slightly narrowed by compression. 



Hamilton group. Bellona, N. Y. 

 Fig. 4. A left valve with the surface nuich distorted. Ijut preserving a very perfect outline. 



Hamilton gronji. Canaudaigua lake. N. T. 

 Fig. 5. The cai-dinal portion of a right valve. 



Hamilton group. Schoharie Co., N. Y. 

 Fig. 6. A left valve of medium size ; imperfect at the cardinal extremities. 



Hamilton group. Delphi Falls, N. Y. 

 Fig. 7. An imperfect right valve preserving the surface characters of the ears, as obtained from the 



matrix after the removal of the specimen. 

 Fig. 8. An enlargement from the surface of a specimen preserving the test. 



Hamilton group. Cfeneseo, Livingston Co., N. Y. 

 Fig. 9. An enlarg-ement of the surface of specimen, fig. 7, taken from the middle of the valve. 

 Fig. 10. A large left valve presei'ving a very perfect outline, with a portion of the test adhering to the lowei- 

 anterior poi'tion. 



Hamilton grouii. Bellona, N. Y. 

 Pig. 11. An enlargement of a portion of the test of the preceding si^ecimen. 

 Fig. 12. An enlai'gement fi-om the surface of a specimen denuded of the test. 



Hamilton group. Crooked lake outlet, N. Y. 



