1857.] 



BUCKMAN OOLITES. 



123 



List of Fossils common to the Inferior Oolite and Cornbrash of 



Gloucestershire* . 



1. 



Amphidesma securiforme, Phill. 



12. 



Modiola gibbosa, M. C. 





YorJc. (Gresslya.) 



13. 



plicata, M. C. 



2. 



decurtatum, Phill. YorJc. 



14. 



Mya literata, M. C. 



3. 



recurvum, Phill. York. 



15. 



Ostrea, undetermined (perhaps 



4. 



Astarte excavata, M. C. 





several species). 



5. 



Avicula inaequivalvis, M. C. 



16. 



Pholadomya Murchisonse, M. C. 



6. 



Cardium citronoideum, Phill. York. 





t. 545. 



7. 



— — dissimile, M. C. 



17. 



gibbosa? 



8. 



, undetermined. 



18. 



Plagiostoma duplicatum, M. C. 



9. 



Isocardia concentrica, M. C. (Ce- 



19. 



Pecten. 





romya). 



20. 



Trigonia costata, Park. 



10. 



minimaf, M. C. 



21. 



clavellata, Park. 



11. Lima gibbosa, M. C. 491. 



The only fossils I have yet found that may be said to be peculiar 

 to the Cornbrash are the Terebratula obovata and T. lagenalis, and 

 even these I cannot help viewing as distinctive in name only, my 

 series of these shells presenting most remarkable gradations ; how- 

 ever, the T. obovata by its quantity and allocation may confidently he 

 appealed to in discriminating this stratum. 



3. The agricultural peculiarities of Cornbrash are highly inter- 

 esting ; usually the term " brash " is one of reproach ; and, if a farmer 

 gets a good crop on " only a brash," he is not a little proud of his 

 management ; here, however, the term points out this rock as a corn- 

 bearing brash, and this is in itself enough to show that a different 

 practical value had been set upon brashes before the principles in- 

 volved had been fairly made out, a fact which may be gathered from 

 the following rent-charge : — 



1st. Rent of stonebrash, Inferior Oolite, from 7s. to 20*. the acre. 

 2nd. „ „ Great Oolite, „ 14 „ 25 „ 



3rd. „ „ Cornbrash „ 20 „ 40 „ 



If we look at the average yield of grain per acre, we shall see that 

 this difference of price is fully justified : — 



Table of Produce. 





1. Stonebrash, 

 Inferior Oolite. 



2. Stonebrash, 

 Great Oolite. 



3. Cornbrash. 



Wheat 



Bushels. 

 15 to 20 

 25 to 30 

 25 to 30 



Bushels. 

 20 to 25 

 30 to 35 

 35 to 40 



Bushels. 

 25 to 30 

 40 to 45 

 45 to 50 





Oats 





If we seek for the cause of these results, we shall at once find 

 them by referring to the analysis before quoted, the fact being that 

 the better brashes not only break down more readily under the action 

 of the atmosphere, but they also contain more of the true fertilizing 



* See also Cotteswolds Nat. Club Proceed., vol. i. p. 265. 

 f One of the commonest shells. 



