PLATE XXIV. 

 Pterinopecten imbecilis. 



Page 75. 

 Fig-. 1. An imperfect left valve, X -. 



Chemung 1 group. Tioga, Tioga Co., Pa. 



Fterinopectex (Aviculopecten) stkictus. 



Page 74. 

 See Plate 82. 

 Fig-. -■ A right valve showing- the form of the shell and the characters of the hinge. 

 Chemung- group. Near Elmira, X. Y. 



Aviculopecten plexus. 



Page 21. 

 Fig. 3. A left valve, showing the general features of the shell. 

 Chemung group. Near Elmira, N. Y. 



Aviculopecten Idas. 



Page 13. 

 See Plate 3. 

 Fig. 4. A right valve. 



Hamilton group. Cayuga lake, N. Y. 



Lyriopecten SOLOX. 



Page 56. 

 Fig. 5. A right valve, imperfect anterior to the beak. The recent discovery of the impression of this valve 

 substantiates the correctness of the restoration of the anterior ear in the figure. 

 Chemung group. Panama, N. Y. 



