§ H. 



KELLOWAY ROCK, AND CORNBRASH. 



503 



part of the oolitic system occur through this part of 

 Wiltshire in their natural order of succession ; as is shown 

 in the following section (Lign. 112), in which the sub- 

 divisions of the Chalk and Oolite, from the Upper or flinty 

 Chalk down to the Oxford clay, are seen in a nearly 

 horizontal and conformable position. 



Lign. 112.— Section from the Wiltshire Chalk-Downs to the Oxford 



Clay. 



1. Upper and Lower White Chalk. 2. Firestone. 3. Gait. 4. Greensand. 



5. Portland Oolite. 6. Kimmeridge Clay. 7. Coral-rag. 8. Oxford Clay. 



14. Kelloway Rock, and Cornbrash. — A bed of 

 gritty arenaceous limestone, a few feet in thickness, is 

 intercalated in the Oxford clay, and is remarkable for the 

 abundance of shells, and other organic remains which it con- 

 tains. It is called the Kelloway rock : hence a common species 

 of ammonite in this deposit is named A, Calloviensis. 



Cornbrash. — Under the Oxford clay a stratum of rubbly 

 hard limestone, from ten to twelve feet thick, is generally met 

 with, which, like the Kelloway rock, swarms with many 

 species and genera of marine shells, associated with other 

 fossils. This bed is provincially termed Cornbrash. I sub- 

 join figures of a few peculiar shells from the neighbourhood 

 of Scarborough in Yorkshire, which were first described by 

 Mr. Bean.* 



* See " A Catalogue of the Fossils found in the Cornbrash Limestone 

 of Scarborough, Yorkshire," by William Bean, Esq.— Mag. Nat.ffist. 

 vol. iii. p. 57. 



