PLATE LII. 



(Figares 1-15 by G. B. Simpson; 16-19 by E. Emmons; 20-36 copies.) 



Genus CLINTONELLA. gen. nov. 



Page 159. 

 ClINTONELLA VAGABUNDA, S|). uov. 



Fig'. 1. A dorsal view of an internal cast retaining the siiell on the umbo of the pedicle-valve. Below the 

 foramen is seen a portion of the lower surface of the hinge-plate. 



Fig. 2. A view of another specimen similarly jireserved, though the hinge-plate is wholly removed. 



Fig. 3. A profile of the same specimen ; showing the normal convexity of the valves and the elevation of 

 the median fol<l on the brachial valve. 



Fig. 4. A ventral view of the same specimen ; showing the depth of the median sinus. 



Fig. 5. The interior of an imperfect pedicle-valve ; showing the teeth and open delthyrium. X 2. 



Fig. 6. The interior of a pedicle-valve ; showing the elevation and curvature of the teeth. X 2. 



Fig. 7. The interior of the umbonal portion of the brachial valve ; showing the divided hinge-plate and 

 the low median ridge. X 3. 



Pig. 8. An internal cast of a pedicle-valve ; showing the muscular area crossed by the plications of the 

 shell. X 2. 



Fig. 9. The interior of the umbonal region of conjoined valves, viewed from in front ; showing the mode 

 of articulation and the bilobed cardinal process. X 3. 



Fig. 10. A cast of the interior of the pedicle-valve ; showing the division of the muscular area into adduc- 

 tor and diductor scars. X 2. 



Fig. 11. An incomplete interior of the brachial valve ; showing the hinge-plate and muscular scars. X 2. 

 Clinton group. Drift of Western NeiB York. 



Genus CCELOSPIRA, Hall. 



Page 134. 



CCELOSPIRA PLICATULA, Hilll. 



See Plate 53. 



Figs. 12-14. Ventral, profile and doreal views of the exterior ; showing contour and character of plication. 



Clinton group. Lockport'N. Y. 



C(ELOSPXRA PLANOCONVEXA, Hall. 

 See Plate 53. 

 Fig. 15. The interior of a pedicle-valve. X H- 



Clinton group. Hamilton, Ontario. 



C(elospira (cf.) HEMisPHiERiCA, Sowcrby. 



Fig. 16. The interior of a pedicle-valve. X 3. 



Clinton group. Near Woleott, iV. Y. 



Genus ANOPLOTHECA, Sandberger. 



Page 129. 



Anoplotheca lepida, Goldfuss. 



Figs. 17, 18. Dorsal and profile views of an average specimen ; showing the slightly concavo-convex contour, 

 the low, sparse plications and fine concentric lineation. X 5. 



Fig. 19. A portion of the interior of a i)edicle-valve ; showing the teeth resting upon the thickened shell- 

 wall, and the median septum grooved for the reception of the extremity of the loop. 

 Middle Devonian. Gerolstei?t, E'lfel. 



