PLATE .XCIII—Continued. 
Grammysia UNDATA. 
Page 379. 
See Plates (31, 64. 
Fig. 21. A left valve. 
Chemung group. Near Olean, N. Y. 
Grammysia oyata. 
Page 358. 
Fig. 22. A specimen retaining both valves in conjunction. 
Corniferous limestone. Delaware, Ohio. 
Grammysia dupucata. 
Fig. 23. A right valve showing surface ornamentations. 
Chemung group. Warren, Pa. 
Fig. 23a. A profile of the preceding. 
Grammysia glabra. 
Page 309. 
Fig'. 24. A partial cast of a left valve showing the muscular scars and lines of growth. 
Chemung group. Warren, Pa. 
Grammysia bisulcata. 
. Page 359. 
See Plates 54, 56. 
Fig. 25. A right valve showing strong concentric undulations of the surface and fine radiating striae. 
Hamilton group. Albany Co., N. Y. 
Grammysia subarcuata. 
Page 375. 
See Plate 61. 
Fig. 26. Anterior view of a specimen showing a very strongly developed lunule. 
Chemung group. 
Grammysia arcuata. 
Page 373. 
See Plates 61, 63. 
Fig. 27. The left side of a specimen showing concentric undulations. 
Hamilton group. Pratt's falls, N. Y. 
Euthydesma SUBTEXTILE. 
Page 3S5. 
See Plate 63. 
Fig. 28. The hinge of a left valve showing the straight ligamental area. 
Fig. 29. An enlargement of the surface from another specimen. 
Portage group. Near Portland Harbor, Chautauqua Co., N. Y. 
