PLATE 25. 
Figs. 1-11. Productella speciosa.... 
1. An impression of the exterior of a dorsal valve, showing the marks of the cardinal process. 
2. The interior of a dorsal valve. 
3 A profile of specimen fig. 2. 
4, 5. Views of ventral valves. 
6, 7. Profiles of specimens figs. 5, 8. 
8. A ventral valve which is broad and depressed and strongly pustulose. 
9.10, 11. Ventral, profile and cardinal views of a very gibbous individual—the specimen from 
which the original description was given. 
Page 
175 
Figs. 12, 13. Productella exanthemata. 168 
12, 13. The interiors of dorsal valves. 
Figs. 14-21. Productella striatula. 177 
14,15. The interiors of dorsal valves. 
16. A profile of specimen fig. 15. 
17, 18. Ventral view and profile of a specimen of symmetrical form, showing scattered spine-bases. 
19, 20, 21. Ventral and cardinal view's and profile of a specimen of broader form—fig. 20, showing 
the muscular impressions. 
Fig. 22. Productella arctirostrata. 182 
22. An exfoliated interior of a dorsal valve, referred with doubt to this species. 
Figs. 23-28. Productella lachrtmosa. 172 
23, 24. Impressions of dorsal valves, one with numerous pustules, and the other nearly desti¬ 
tute of pustules. 
25, 26, 27. Ventral valves of this species; the figures 25 and 27 show some remains of spines 
and elongate pustules; 26 is a broader form with fewer pustules. 
28. The ventral valve of a young individual of the same species, showing numerous elongate 
pustules. 
Figs. 29-32. Productella lachrtmosa var. lima. 174 
29. A ventral valve which is regularly convex and showing short pustules. 
30. A profile of the same. 
31. A shorter and more quadrate form with a mesial depression; the pustules very symmetrically 
arranged. The specimen corresponds to the original description of P. lima, Conrad. 
32. A cardinal view of the same specimen, showing the muscular markings and cavities left by 
the teeth. 
-41. Productella lachrtmosa var. stigmata. 174 
An impression of a very large dorsal valve. 
An impression of a more concave dorsal valve, showing the form of cardinal process. 
A,profile of the same. 
An impression of a more symmetrical dorsal valve, showing regular and larger pustules, and 
also an impression of the cardinal process. 
A very convex ventral yalve, showing pits left by the spine-bases. 
A cardinal view of the same. 
A ventral valve preserving a greater number of spine-bases. 
A profile of the same. 
A cardinal view of the same, showing muscular impressions. 
Figs. 33 - 
33. 
34. 
35. 
36. 
37. 
38. 
39. 
40. 
41. 
