PLATE 24. 
PRODUCTELLA RARISPINA. 
Page 
170 
Pigs. 1-9. 
1. The ventral valve of a young individual. 
2, 3, 4. Three views of a,n adult individual, showing an irregular fold on the ventral valve. 
5. A ventral valve, preserving two of the spines and the bases of several others. 
6. A ventral valve, which is unusually symmetrical, and retains the marks of very few spines. 
7. A cardinal view of a ventral valve. 
8. The interior of a dorsal valve. 
9. Profile of specimen fig. 8. 
Figs. 10-16. PRODUCTELLA BOYDII . 169 
10. The ventral valve of a young individual. 
11. 12. The interior of dorsal valves, showing pustules from the indentations of the exterior. 
13 -15. Ventral valves of this species, preserving some of the spines. 
16. A profile view of the specimen fig. 15. 
Fig. 17-29. PRODUCTELLA HIRSUTA.. . 166 
17. The ventral valve of a young individual. 
18. 19. Ventral valves of large individuals. 
20. An impression of a dorsal valve. 
21, 22. Ventral valves preserving some of the submarginal spines. 
23. A profile of the specimen fig. 22. 
24. A symmetrical ventral valve with short hinge line. 
25. A profile view of the preceding. 
26. A large and somewhat distorted ventral valve preserving some of the submarginal spines. 
27. The interior of a dorsal valve with cardinal process. 
28. An enlargement of the cardinal process from fig. 27. 
29. An enlargement of a portion of the surface, from a well preserved specimen. 
Figs. 80-37. PRODUCTELLA HIRSUTA var. RECTISPINA . 168 
30. The dorsal valve of a small individual. 
31. A convex ventral valve. 
32. A large ventral valve. 
33. An impiession of the exterior of a large dorsal valve. 
34. A large and somewhat distorted ventral valve. 
35. A profile view of the same. 
36. The interior of a large ventral valve from which the shell has been mostly removed, pre¬ 
serving the submarginal spines. 
37. The interior of a dorsal valve from an impression in the stone. 
