PLATE XT.IX—Continued. 
Pal^eoneilo feounda. 
Page 336. 
Figs. 13, 15-17. Figures illustrating the usual forms in this species. 
Fig. 18. A right valve of shorter form. 
Hamilton group. Near Cumberland, Md. 
Fig. 19. The right side of a cast of the interior, showing the muscular scars, pallial line and crenulated 
hinge. Hamilton group. Near Cumberland, Md. 
Fig. 20 The left side of a specimen similar to the preceding. 
Hamilton groitp. Near Cumberland, Md. 
Fig. 21. A gutta-percha impression from the specimen fig-. 20. 
Fig-. 22. An enlarg-ement of a part of the hinge, from the preceding. 
Fig. 23. An enlargement of the surface striae, from the specimen lig. 18. 
Fig-. 24. The cardinal view of a cast of the interior, showing the crenulated hinge and muscular scars. 
Hamilton group. Near Cumbeiland, Md. 
Pal.eoneilo muta. 
Page 337. 
Figs. 25, 26. Two valves presenting the ordinary form of the smaller individuals. 
Hamilton group. Bellona and shore of Canandaigua lake, N. Y. 
Fig. 27. A left valve of more elongate form. 
Hamilton group. Shore of Seneca lake, N. Y. 
Fig-. 28. A right valve. 
Hamilton group. Shore of Canandaigua lake, N. Y. 
Fig-s. 29, 30. Left and right valves of large individuals. 
Fig. 31. A left valve of unusually short form with the concentric lamellae very strongly developed. 
Hamilton group. Shore of Skaneateles lake, N. Y. 
Fig. 32. An enlargement of the surface, from the preceding-. 
PALiEONEILO FILOSA. 
Page 343. 
Figs. 33-38. A series of right and left valves preserving the usual form of this species. 
Lower Chemung' group. Near Ithaca, N. Y. 
