PLATE 25. 



Page 



Figs. 1 - 11. Prodcctella specios.v 17:') 



1. An impression of the exterior of a dorsal valve, showing the murks of the cardinal process. 



2. The interior of a dorsal valve. 

 3 A pro81e 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. 



Figs. 12, 13. Productklla exanthemata 1(53 



12, 18. 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 views 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 witli doubt to this species. 



Figs. 23-28. Pkoductella lacurymosa 172 



2.3, 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 yoimg individual of the same species, showing numerous elongate 



pustules. 



Figs. 29-32. Pkoductella lachrymosa var. liaia 174 



29. A ventral valve which is regularly convex and sliowing short pustules. 

 80. A profile of the same. 



31 . A shorter and more quadrate form with a mesial depression ; the pustules very symmetrically 



arranged. The specimen con-esponds 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. 



Figs. 33-41. Productella lachrymosa var. stkjmata 174 



33. An impression of a very large dorsal valve. _ 



34. An impression of a more concave dorsal valve, showing the form of cardinal process. 



35. A profile of the same. 



86. An impression of a more symmetrical dorsal valve, showing regular and larger pustules, and 



also an impression of the cardinal process. 



87. A very convex ventral valve, showing pits left by the spine-bases. 

 38. A cardinal view of the same. 



89. A ventral valve preserving a greater nuinlicr of sjiinc-lKisos. 



40. A profile of the same. 



41. A cardinal view of the same, showing imistiilar impressions. 



