PLATE II. 



BlLOCULINA. — PLANISPIRINA . 



Diam. Page 



Figures 1-3. — Planispirina sigmoidea, n. sp., . . . . 197 



Fig. 1 a, 2. Lateral aspect ; b, oral aspect, . x 40 



Fig. 3. Transverse section, showing the arrangement of 

 the chamhers. A similar section viewed by 

 transmitted light is figured on p. 194, . x 30 



,, 4. — Biloculina sphcera, d'Orbign . . . x 35 141 



a, Front aspect ; b, lateral aspect. 



,, 5, 6. — Biloculina bulloides, d'Orbigny, . . . . 142 



Fig. 5. a, Front aspect ; b, oral aspect, . . x 25 



Fig. 6. Transverse section of a smaller specimen, . x 40 



,, 7, 8. — Biloculina ringens, Lamarck, sp., . . x 25 142 



a, Front aspect ; b, oral aspect. 



9. — Biloculina elongata, d'Orbigny, . . x 45 144 



«, Front aspect ; b, oral aspect. 



,, 10,11. — Biloculina depressa, d'Orb., var. murrhyna, Schwager, x 50 146 



Figs. 10, 11. a, Front aspect; b, oral aspect. 



,, 13, 14. — Biloculina Icevis, Defrance, sp., . . . . 146 



Fig. 13. a, Front aspect ; b, oral aspect, . x 30 



Fig. 14. a, Front aspect; b, oral aspect, . x 20 



„ 12,15-17. — Biloculina depressa, d'Orbigny, . . . 145 



a, Lateral aspect ; b, oral aspect. 



Fig. 12. x 30 diam.; fig. 15 x 40 diam.; fig. 16, . x 35 



Fig. 17. Transverse section of the shell, . . x In 



