PLATE LXXXVIII. 



LeIOPTERIA COiN'KADr. 



Page 159 

 See Plate 20. 

 Vig. 1. A left valve rshdwing' strong coneenti'ic undulations. 



Hamilton group. LronardsvlUe, Madison Co., iV. Y. 

 Fig. 2. A small left valve. 



Hamilton groujj. Caiuindaigua lake, iV. Y. 

 Fig. 3. A large left vah-e imperfect on the anterior side. This tigiire is given in i-on-eftion of tig. 4. phite 20. 

 Fig. 4. An imperfect right \'alve. 



Hamilton group. SkanedtelfK lake, N. Y. 



Leiopteria Dekayi. 



Page 164. 

 See Plates 19 and 20. 

 Fig. 5. The internal njould of a specimen preserving both valves, and showing the vertical plate just 

 anterior to the beaks. 



Hamilton group. F'uUunhaiii, iScho/iarit Co., N. Y. 

 Fig. 6. A large left vahe with the wing partially I'estored. 

 Hamilton group. iSclioharie Co., N. Y. 

 Fig. 7. An enlargement of the surface on the umbonal slope of the specimen tig 10. 

 Fig. 8. A left valve jiresei-ving the sti-iated ligamental area. 

 Fig. 9. A cardinal view of a portion (.f both valves showing the deep sulci anterior to the beaks. 



Hamilton group. Ftdtonham, Sc-lioliarie Co., N. Y. 

 Fig. 10. A small left valve showing the fine concenti'ic striae of the test. 

 Hamilton group. Delphi. Onondaga Co., N. Y. 



Leiopteria Torreyi. 



Page 174. 



See Plate 22. 

 Fig. 11. A left valve of this species. 



Chemung group. Paimina, CJ/autauqaa Co., N. Y. 



Leiopteria Troosti. 



Page 1()7. 

 Fig. 12. A left \alve showing the form and surface characters. 

 Fig. 13. A portion of the surface enlarged to thi-ee diameters. 

 Hamilton grouj). ScJioJiarie Co., N. Y. 



Leiopteria Gabbi. 



Page 16U 

 Fig. 14. A left \alve showing the form and sui'face characters. 

 Hamilton group. Cayuga lake, N. Y. 



