PLATE I,XXX—Continued. 
Eunella simulator. Hall. 
Fig-. 27. Dorsal view of a specimen which has been cut to show the loop, the recurved branch of which is 
not retained. X 2. 
Hamilton group. Widder, On:tario. 
Eunella LiNCKLiENi, Hall'. 
Figs. 28, 29. Dorsal and profile views of a normal mature example. 
Hamilton gj-oup. Canandaigua Lake, New York. 
Fig. 30. The loop of a varietal form of the species. 
Hamilton group. Thundxr Bay, Michigan. 
Figs. 31, 32. Ventral and dorsal views of an internal cast; showing the cavities left by the dental and hinge- 
plates and the diverging muscular or vascular lines on both valves. 
Hamilton shales. Hamilton, New York. 
Eunella Harmonia, Hall. 
Figs. 33, 34. Dorsal and profile views of one of the original specimens. 
Corniferous limestone. Falls of the Ohio. 
Fig. 35. Dorsal view of a broader shell, ground down to expose the loop. 
Corniferous limestone. Cayuga, Ontario. 
Subgenus CEANHINA, s.-gen. nov. 
Page ‘297. 
Cran.®na Iowensis, Calvin. 
Fig. 36. Dorsal view of a large example from which the shell has been partially exfoliated, exposing the 
musculai- mai-kings of the bi-achial valve. 
Figs. 37, 38. Pi-ofile and dorsal views of a normal individual retaining the shell intact and showing the del- 
tidial plates. 
Fig. 39. Dorsal view of an internal cast; showing the muscular scars of the bi-achial valve and the cavities 
left by the dental lamellae of the pedicle-valve. 
Hamilton gi-ouji. Rockford. loioa. 
