PLATE LXXXVIII. 
Leiopteria Conradi. * 
Page 159. 
See Plate 20. 
F,ig. 1. A left valve showing strong concentric undulations. 
Hamilton gToup. Leonardsville, Madison Co., N. Y. 
Fig. 2. A small left valve. 
Hamilton group. . Canandaigua lake, JV. Y. 
Fig. 3. A large left valve imperfect on the anterior side. This figure is given in correction of fig. 4, plate 20. 
Fig. 4. An imperfect right valve. 
Hamilton group. Skaneateles lake, N. Y. 
Leiopteria Dekayi. 
Page 164. 
See Plates 19 and 20. 
Fig. 5. The internal mould of a specimen preserving- both valves, and showing the vertical plate just 
anterior to the beaks. 
Hamilton group. Fultonham, Schoharie Co., N. Y. 
Fig. 6. A large left valve with the wing partially restored. 
Hamilton group. Schoharie Co., N. Y. 
Fig. 7. An enlargement of the surface on the umbonal slope of the specimen fig. 10. 
Fig. 8. A left valve preserving the striated ligamental area. 
Fig. 9. A cardinal view of a portion of both valves showing the deep sulci anterior to the beaks. 
Hamilton group. Fultonham, Schoharie Co., N. Y. 
Fig. 10. A small left valve showing the fine concentric striae of the test. 
Hamilton g-roup. Delphi, Onondaga Co., N. Y. 
Leiopteria Torreyi. 
Page 174. 
* See Plate 22. 
Fig. 11. A left valve of this species. 
Chemung group. Panama, Chautauqua Co., N. Y. 
Leiopteria Troosti. 
Page 167. 
Fig. 12; A left valve showing the form and surface characters. 
Fig. 13. A portion of the surface enlarged to three diameters. 
Hamilton group. Schoharie Co., N. Y. 
Leiopteria Gabbi. 
Page 169. 
Fig. 14. A left valve showing the form and surface characters. 
Hamilton group. ' Cayuga lake, N. Y 
