PLATE XLV. 



BlGENERINA. — PAVONINA. — SPIROPLECTA. 



Figures 1-4. — Bigenerina capreolus, d'Orbigny, sp., 



Figs. 1 a, 2. Adult specimens, lateral aspect ; 1 b, oral 



aspect. 

 Fig, 3. Young specimen, lateral aspect; fig. 4, oral 



aspect. 



Diam. 

 x 20 



Page 

 372 



„ 5-8. — Bigenerina pennatula, Batsch, sp., 



Figs. 5, 6, 7. Lateral aspect ; fig. 8, oral aspect. 



X 20 



373 



9-16. — Bigenerina robusta, Brady, 



Figs. 9, 10. Lateral aspect; figs. 11, 12, oral aspect. 

 Fig. 1 3. Specimen laid open longitudinally to show the 



interior. 

 Fig. 14. Test fractured transversely. 

 Figs. 15, 16. Monstrous specimens, showing different 



forms of aperture. 



x 14 



371 



„ 17-21. — Pavonina Jiabelliformis, d'Orbigny, 

 Fig. 17. Lateral aspect, 

 Figs. 18, 19. Lateral aspect; figs. 20, 21, oral aspect, 



x 50 

 x 60 



374 



.. 22, 23. — Spiroplecta annectens, Parker and Jones, . 



Figs. 22, 23 a, Lateral aspect ; ft, oral aspect. 



x 60 



376 



24. — Spiroplecta americana, Ehrenberg, 



a, Lateral aspect ; b, oral aspect. 



x 60 



376 



„ 25-27. — Spirop)lcct<i biformis, Parker and Jones, sp., 

 Fig. 25. Lateral aspect, 

 Figs. 26 a, 27. Lateral aspect ; 26 h, oral aspect, 



x 100 

 x SO 



376 



