PLATE I. 

 Fig. 



I. Lingula Beanii, Phil., natural size. 



la, b. „ „ interior of larger valve. 



1c, d. „ „ „ smaller valve. 



2a, b. Orbicula Townshendi, Forbes, MS., natural size. 



3. Orbicula Humphresiana, Sow., natural size. 



3a, b. „ „ enlarged illustrations. 



4. 5. 6. 7. Crania antiquior, Jelly, natural size. 



8. ,, „ an enlarged illustration. 



9. Crania Moorei, Dav., natural size. 



9a, b. „ „ enlarged illustrations of the upper valve. 



10. Thecidea Moorei, Dav., several specimens attached to Bhynchonella serrata. 

 10a,b,c,d,e. „ „ enlarged illustrations. 



11. Thecidea triangularis, B"Orb., natural size, from the Lias. 

 \\a, b. „ „ enlarged figures. 



12. „ „ natural size, from the Inferior Oolite. 



13. Thecidea Mediterraneum, Bisso, recent species, natural size. 



14. Thecidea rustica, Moore, MS., natural size. 



14a, b. „ „ enlarged representations of the exterior and 



interior of the smaller valve. 



15. Thecidea Bouchardii, Lav., natural size, from specimens found in the Lias 



near Ilminster. 

 15a. „ „ enlarged interior of attached valve. 



[■enlarged illustrations of Th. Bouchardii. 

 *■ ' • >> >> J 



18. Leptsena Moorei, Dav., natural size, Upper Lias, Ilminster. 



18a, b, c, d, e. „ „ enlarged illustrations of exterior and interior of both 



valves. 



19. Leptgena Tearcei, Dav., natural size, from a specimen found in the Upper Lias. 

 19a, b. „ „ enlarged illustrations. 



20. Leptspna granulosa, Dav., natural size, from the Upper Lias. 

 20a, b. „ „ enlarged illustrations. 



21. Leptsena liasiana, Bouchard, natural size. 

 21a. ,, „ enlarged figure. 



22. Leptsena Bouchardii, Dav., natural size, from the Upper Lias, near Ilminster. 

 22a, b. „ „ enlarged illustration of exterior of both valves. 

 22c. „ „ „ ., of interior of smaller valve. 



