PLATE 95 A, 
Page 
Fig. 1. UnYNCHOSPIRA RECTIROSTRA. 485 
1 a, b } c. Dorsal, ventral and profile views of a specimen of this species. 
Fig. 2, 3, 5 & 6. Merista (Camarium) typum. 487 
2 a. Dorsal view of a specimen of this species. 
2 b. Profile view of the same. 
3. Interior of the ventral valve, showing the transverse arching septum. 
5. A longitudinal section of fig. 3. 
6. A cast of the interior of a valve similar to fig. 3. 
Fig. 4. Merista (Camarium) elongatum. 488 
4. The interior of a ventral valve of this species : the sides of the valve, and a part of the 
arching septum, have been broken away. 
Fig. 7 - 11. Riiynciiospira Formosa. 485 
7. Interior of the ventral valve of a specimen of this species. 
8. Interior of the dorsal valve, enlarged to two diameters, to show the broad cardinal process 
which covers the extremities of the beak. and. when the valves are closed, passes beneath 
the deltidial area of the opposite valve. The bases of the crura are shown on each side at 
the base of the cardinal process, and the short median septum also is shown. 
9. Profile view of the same, showing the cardinal and crural processes. 
10. The upper part of the two valves connected in their natural relations to each other, and 
showing the manner of articulation. 
11. A longitudinal section, showing the foramen, the deltidium, and the cardinal process of 
the opposite valve lying beneath it; the crura first bending downwards, and then re¬ 
curved into the dorsal valve and continued in the spire, with the descending process e, 
which forms, with the opposite one, a connecting filament between the two spires. 
Fig. 13 & 14. Stropiiodonta intermedia*. 482 
13. The exterior of the dorsal valve. 
14. The interior of the same. 
Fill. 15 -10. Stropiiodonta magnificat 482 
o 
15. A dorsal view, showing the area, which is imperforate and striate. The specimen is below 
the medium size which this shell usually attains. 
16. Ventral view of the same : the margins are broken, and the outline is consequently im¬ 
perfect. 
17. The interior of a ventral valve of the same species, showing a central pit or foramen. 
18. View of the area when the linear foramen is closed. 
19. Enlargement of the striae, showing their mode of bifurcation, and the puncta which are 
very regularly interposed between the stria;. 
Fig. 20 & 21. Ortiiis cumberlandia. 481 
20. The exterior of a ventral valve of this species. 
21. The interior of a smaller ventral valve of the same. 
* This species possesses tlie cardinal process of STRornonoXT.v, with the dental lamellae of Stueptoiuiynciius. 
| This species may be compared with Ortiiis hippnrionyx, page 407. The striae, however, arc more sharply elevated 
and less curved towards the hinge-lina, while the muscular impression is not distinctly bilobate as in that species. 
