PLATE XII. 



Fig. 

 1. 



2. 

 3, 4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 



10,17 



18. 



19. 



20. 

 21. 



Terebratula plicata, Buckman. 



From the Inferior Oolite, in the collection of the 

 Geological Society, and in that of Mr. Morris. 

 These are the two largest specimens of the 

 species with which I am acquainted. 



Smooth specimens; the frill or plication appears 

 only at a more advanced age. 



Terebratula fimbria, Sow. From the Inferior Oolite. A very large specimen. 



Interior. 



Young specimen, quite smooth. 

 A young shell. 



Terebratula cardium, Lamarck. From the Great Oolite, Bath. 



From the Great Oolite, Bath. 

 ,, „ A curious specimen, illustrating that, even some- 



times at an advanced age, the plaits bifurcate. 

 „ „ Young shell, plaits bifurcating. Ter.furcata, Sow. 



„ „ Interior. 



Terebratula flabellum, Defrance. From the Bradford Clay, near Bradford. 

 „ „ Enlarged illustrations. 



Interior. 



