PLATE LXXXI. 



Globigerina. — Oebulina. 



Diam. Page 



Figure 1. — Globigerina dutertrei, d'Orbigny, . . x 50 (301 



Bottom specimen ; a, superior aspect ; b, inferior 

 aspect ; c, peripheral aspect. 



,, 2, 3. — Globigerina bulloides, var. triloba, Reuss, . x 50 



Bottom specimens. 



,, S-2G. — Orbulina universa, d'Orbigny, 



Figs. 8-11. Bottom specimens; fig. 10, small dark- 

 coloured variety common in shallow water on the 

 British coast, . . . . x 50 



Figs. 12-14. Surface specimens, . . x 50 



Figs. 15-17. Small bottom specimens in which the 

 Globigerine shell is not completely enveloped 

 by the Orbuline chamber, . . x 50 



Figs. 18, 19. Internal Globigerine shells partially filled 



with sarcode; from balsam-mounted specimens, x ->0 



Figs. 20, 21. Two-chambered specimens. Such forms 

 constitute the Globigerina bildbata of 

 d'Orbigny, . . . . x 50 



Figs. 22, 23. Portions of the test more highly magni- 

 fied ; showing (22) the large and small perfora- 

 tions, and (23) a granular or tuberculate condi- 

 tion of the exterior, . . • x 100 



Fig. 24. Portion of a spinous shell, . x 50 



Fig. 25. Bottom specimen with a general aperture (?) ; 



copied from Williamson, . . x 50 



Fig. 26. Bottom specimen, showing the laminated 



condition of the walls, . . x 50 



595 



„ 4, 5. — Globigerina helicina, d'Orbigny, . . . x 50 605 



Fig. 4. Inferior aspect ; fig. 5, superior aspect. 



,, 6, 7. — Globigerina, — wild-growing monstrous forms, . x 50 593 



Bottom specimens. 



G08 



27. — Orbulina porosa, Terquem, 



50 611 



