PLATE XXII. 
Leptodesma ? sp. inclet. 
Fig. 1. An obscure right valve of an indeterminate character. 
Chemung group. Ithaca, N. Y. 
Leptodesma complanatum. 
Pag e 227. 
Fig. 2. The left valve described. The strise should turn backward along the hinge posterior to the beak. 
Chemung group. Pliilipsbury, Alleghany, Co., N. Y. 
Leptodesma Beck:. 
Page 185. 
Fig. 3. A large right valve. 
Chemung group. Coming, Chemung Co., N Y. 
Fig. 4. A smaller imperfect example. 
Chemung group. Near Portville, Cattaraugus Co., N. 1'. 
Fig. .5. A small left valve showing the form and proportions of the shell. 
Chemung group. Corning, N. Y. 
Letopteria Torreyi. 
• Page 174. 
See Plate 8S. 
Figs. 0, 7. Two left valves, fig, 7, showing the characters of the species. 
Chemung- group. Fig. 6, front Panama; fig. 7, from Salamanca, N. Y. 
Leptodesma Mather r. 
Page ! 1031 1 
See Plate S9. 
Fig. 8. An imperfect left valve of medium size. , 
Fig. 9. A right valve. 
Fig-. 10. A small left valve. The body of the valve; is represented as too broad. 
Chemung group. Bradford, McKean Co., Pa. 
Leptodesma potens. 
; ' Page 188. 
See Plates 21 and 89. 
Fig. 11. A right valve. 
Chemung group. Napoli, Cattaraugus Co., N. Y. 
Fig. 12. A similar left valve. The extremity of the wing should be represented as acute as in fig. 19. 
Chemung group. Near Clean, N. Y. 
Fig. 19. A large left valve. 
Chemung group. Portville, Cattaraugus Co., N. Y. 
Fig. 20. A more elongate form referred to this species with some doubt. 
Chemung group. Randolph, Cattaraugus Co., N. Y. 
Fig. 21. A large elongate left valve. 
Chemung group. Near Cassadaga, Chautauqua Co., N. Y. 
Leptodesma umbonatum. 
. Page 108. 
See Plate 90. 
Fig. 13. The left valve described. Another figure of this specimen is given on plate 90, fig. 9. 
Chemung group. Twenty Mile creelc, Chautauqua Co.', N. Y. 
