PLATE LII. 



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



Genus CLINTONELLA. gen. nov. 



Vane 159. 



Clintonella vagabunda, s|). nov. 



Fig. 1. A dorsal view of an internal cast i-etaining the shell on the umbo of the pe<licle-valve. Below the 



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

 Fig. 2. A view of another specimen .similarly preserved, 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 fold on the brachial valve. 

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

 Pig. 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 ndge. 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. 

 Pig. 10. A cast of the interior of the pedicle-valve ; showing the division of the muscidar area into a<lduc- 



tor and diductor scars. X 2. 

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

 Clinton group. Di-ift of Western Nexo York. 



Genus CCELOSPIRA, Hall. 



I'age \U. 



CoiLOSPIRA plicatula, Hull. 

 See Plate 53. 

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

 Clinton group. Lockport'N. Y. 



CcELOSPIRA planoconvexa, Hall. 



See Plate 53. 

 Fig. 15. The interior of a pedicle-valve. X 1^. 



Clinton group. Hmnilton, Ontario. 



Ccelospika (cf.) HEMISPH^RICA, Sowerby. 



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



Clinton group. Near Wolcott, N. Y. 



Genus ANOPLOTHECA, Sandberqek. 



Page 129. 



Anoplotheca lepida, Goldfuss. 



F"igs. 17, IS. Dorsal and profile views of an avei-age specimen ; showing the slightly concavo-convex contour, 

 the low, spar.<?e plications and tine concentric lineation. X 5. 



Fig. 19. A portion of the inlerior 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. GcroUtein, Eifel. 



