PLATE LXXIX—CoQtinued. 
Genus ORISKANIA, gen. nov. 
Page 265. 
Oriskania navicella, sp. nov. 
Pigs. 25-27. Dorsal, profile and ventral views of the exterior ; showing the elongate form and plano-convex 
contour of the species. 
Oriskany sandstone. Rondout, Nexo York. 
Genus ROMINGERINA, gen. nov. 
Page 265. 
Romingerina Julia, A. Winchell. 
Fig. 28. Dorsal view of a large internal cast; showing the form of the shell and the impression of the 
divided hinge-plate. X 2. 
Figs. 29, 30. Dorsal and profile views of a smaller internal cast; showing the convexity of both valves. X 2. 
Marshall group. Pointe aux Barques, Michigan. 
Genus CRYPTONELLA, Hall. 
Page 256. 
Crvptonella (?) inconstans, Herrick. 
Ifigs. 31, 32. Dorsal and ventral views of a small internal cast; showing the form of the shell and muscular 
markings. 
Waverly group. Medina coxonty, Ohio. 
Genus BEECHERIA, gen. nov. 
Page 300. 
Beecheria Davidsoni, nom. iiov. 
Figs. 33, 34. Dorsal and profile views of an average specimen. 
Fig. 35. Dorsal view of a more elongate shell. 
Fig. 36. The internal cardinal structure exposed by the removal of a portion of the pedicle-valve ; show¬ 
ing the absence of dental plates in the valve, and the structure of the loop. X 3. 
Carboniferous limestone. Windsor, Nova Scotia. • 
Genus HARTTINA, gen. nov. 
P.age 292. 
Harttina Anna, Hartt. 
Figs. 37-39. Dorsal, profile and ventral views of a well-preserved example ; showing the subplano-convex 
contour of the valves. 
Carboniferous limestone. Windsor, Nova Scotia. 
Genus CENTRONELLA, Billings. 
Page 265. 
CeNTRONELLA (?) NAVICELLA, Hall. 
Figs. 40-42. Dorsal, profile and ventral views of the oi-iginal example, which is referred with doubt to this 
genus. 
Upper Devonian. Rockfm'd, loioa. 
