PLATE XLII—Continued. 
Goniophora Ida. 
Page 300. 
See Plate 65. 
Fig - . 13. A specimen retaining both valves connected by the hinge ligament. 
Hamilton group. Bellona, N. Y. 
Goniophora subrecta. 
Page 304. 
See Plate 44. 
Figs. 14, 15. Two left valves. 
Chemung group. Charlotteville and Jefferson, Schoharie Co., N. Y. 
Microdon (Cypricardella) tenuistriatus. 
Page 310. 
See Plates 73, 74. 
Fig. 16. A cardinal view of a specimen retaining both valves. 
Hamilton group. Cumberland, Md. 
Microdon (Cypricardella) bellistriatus. 
Page SOS. 
See Plates 73, 74. 
Fig. 8b. A short and broad right valve, showing the hinge and the cardinal teeth. 
Hamilton group. Ludlowville, iV". Y. 
Fig. 17. A cardinal view of a small specimen preserving both valves. 
Hamilton group. Cumberland, Md. 
Fig-. 18. A specimen showing the valves opened and attached along the hinge-line. 
Hamilton group. Bellona, N. Y. 
Fig. 19. An unusually short and broad form. 
Hamilton group. Shore of Cayuga lake, N. Y. 
Fig-. 20. An enlargement of the hinge of a right valve. 
Hamilton group. Shore of Seneca lake, N. Y. 
Microdon (Cypricardella) major. 
Page 307. 
Fig. 21. A right valve showing the form of the shell and the surface markings. 
Corniferous limestone. Delaware, Ohio. 
Microdon (Cypricardella) complanatus. 
Page 311. 
See Plate 74. 
Fig. 22. The left side of a specimen which is a partial cast of the interior, showing the muscular scars and 
pallial line. 
Hamilton g-roup. Norwich, N. Y. 
