ri.ATlO I.XXXVIII— Coiitiiiuoil. 



Lkiopticria Sayi. 



I'ase Ki. 

 Viff. 1") All iiiiiii'ifcrt left valvi! preserving very line c-oncentric lines. 



llainilton gTOiip. NaHmi's Laitiling, (Jayuga lake, A. 1'. 

 I'if;. K;. The left val\e uf a specimen preserving' lii tli valves, showing' the extent of llie win- and general 

 form of the shi'll. i i i 



Hamilton gron]). LhiiwjstoH Co., iV. Y. 

 lijr. 17. 'I'lie rij,'ht valve of a larfje specimen with the valves partially opened. 



Hamilton {,'ronp. Bdloiia, iV. Y. 

 V'li:. 18 A lei t valve \ ireservinf,' the auricle ami wing nearly entire. The Vioily of the .shell has l)een subjected 

 to pre.ssure and distorlion in the soft shale and does not represent the true torm and obliquity. 



Hamilton group. Belloiia, N. Y. 

 Fig. l'.». An imperfect left valve as preserved in a coarse gi-it. 



Hamilton group. Leonardsville, MndUon Co., iV. Y. 

 Fig. '20. A small left valve of consideralile t;ibbosity. 



Hamilton group. iScltoharie Co., IV. Y. 



Leiovteria Gkeeni. 



Page 160. 

 See Plate 20. 

 Fig. 21. A large left valve. The figure is restored on the l)eak and anterior side. 



Hamilton group. Bellona, Yates Co., N. Y. 

 Fig. 22. An imperfect right valve. 



Hamilton group. Canandaiffua lake, N. Y. 



LeIOPTERIA BlGSBYI. 



Page 1U5. 

 See Plate 20. 

 Fig. 23. A small right valve referred to this species. 

 Hamilton group. N. Y. 



Leioptekia Leai. 



Page im. 

 Fig. 24. A small left valve. 



Fig 2.5. A larger irapei'fect left \alve associated with the jireceding. 

 Hamilton group. SchoTiarie Co., JV. Y. 



Leiopteria jMixchelli. 



Page IfiG. 



See Plate 20. 



Fig. 26. A lar.e imperfect left valvi^ ius obtained from the impression of the exterior of the valve in the 



matrix. 



Hamilton giiiiip. HcJioharle Co., N. Y. 



Leiopteria Rafinesquii. 



Page 101. 

 See Plates 15 and 20. 

 Fig. 27. A nearly entire left valve showing the form and the strong concentric undulations. 



Hamilton group. Belloiia, N. Y. 

 Fig. 28. Aright valve referred to this specieS. The specimen is impei-fect at the beak and extremity of 

 the wing. 



Hamilton group. Lnonardsville, N. Y. 



Leiopteria linquiformis. 



Page 173. 

 Fig. 20. A left valve, denuded of the test, showing the general form with the jiallial line and muscular 

 imjM'essioii. 



Chemung group. Aorth of Bing/ia niton, N. Y. 



