The figures are of natural size unless the amount of enlargement is stated. 
PLATE I. 
Genus Nucutana, Link. 
FIGS. 
1—3. N. spathulata (Forbes). (P. 1.) 
1. The Type. Atherfield Clay, Atherfield. Mus. Geol. Soc., No. 2112. 
2. Crackers, Atherfield. Wiltshire Collection, Woodwardian Museum. a, right 
valve; b, anterior of same; ¢, same valve x 2. 
3. Same horizon, locality, &c. Left valve. 
4, 5. N. subrecurva (Phil.). Speeton Clay, Speeton. Leckenby Collection, 
Woodwardian Museum. (P. 2.) 
4. a, left valve; 6, anterior view; ¢, dorsal. Figured by Gardner. 
5. a, right valve; 0b, dorsal view. 
6, 7. N. speetonensis, Woods. Speeton Clay, Speeton. Museum of Practical 
Geology, No. 6412. (P. 3.) 
6. a, left valve; 6, ornament x 2. 
7. a, left valve; 6, dorsal view. 
8—14. N. [? Yoldia| scapha (dOrb.). 8—13, Atherfield Clay, Sevenoaks. 
(Be 3:) 
8. Collection of C. J. A. Meyer. a, right valve; 0, dorsal view; ec, ornament x 2. 
Figured by Gardner. 
9. British Museum, No. L 9280. Left valve. 
10, 11. = Right valves. 
12. Collection of C. J. A. Meyer. Left valve. 
13. — — Right valve. 
14. Speeton Clay, Speeton. Woodwardian Museum. Left valve. 
15—17. N. Seeleyi (Gardn.). Speeton Clay, Speeton. (P. 5.) 
15. The Type. Leckenby Collection, Woodwardian Museum. a, left valve; 3, 
dorsal view. 
16. Woodwardian Museum. a, left valve; 6, dorsal. 
17. Bed C3. Collection of G. W. Lamplugh. a, left valve; 6, dorsal outline. 
18—24. N. solea (d’Orb.). Gault, Folkestone. (P. 5.) 
18,19. Wiltshire Collection, Woodwardian Museum. Right valves. 
20. Montagu Smith Collection, Woodwardian Museum. Interior of left valve x 2. 
21—24. British Museum, No. L 4974. 21, 28, and 24, right valves; 22, left valve. 
95—27. N. Marie (d’Orb.). Gault, Folkestone. (P. 6.) 
25. British Museum, No. L 4973. a, right valve; 6, dorsal outline; ¢, same x 2. 
26. British Museum, No. L 4973. a, right valve; b, same x 3. 
27. Woodwardian Museum. Right vaive. 
28—-32. N. lineata (Sow.). 28—31, Greensand, Blackdown. (P. 7.) 
28. The Type, Bristol Museum. a, right valve; 0, dorsal view. 
29. Collection of C. J. A. Meyer. Lett valve. 
30. Wiltshire Collection, Woodwardian Museum. Left valve. 
81. _- _- a, outline of left valve; 6, same 
x 2; ¢, same, dorsal, x 2; d, interior of another specimen, right valve, x 3. 
32. Lower Greensand, Atherfield. Gardner Collection, British Museum, No. L 5109. 
a, outline of right valve; 6, same x 2; c, dorsal view xX 2. 
3—35. N. angulata (Sow.). Greensand, Blackdown. (P. 8.) 
33. Collection of C. J. A. Meyer. a, outline of right valve; 6, same X 4; ¢, another 
specimen, dorsal view, x 4. 
34. a, outline of right valve; 6, same x 4. 
35. The Types, British Museum, No. 43213. a, outline of right valve; 6, same x 3; 
ce, dorsal view of another specimen x 3; d, interior of another specimen, right 
valve, x 3. 
