BLUE CHALK MARL. 85 



" A belt of blue clay appears on the north, the geological relation of 

 which to the preceding has not been ascertained. It invariably accom- 

 panies the malm rock in the direction here pointed out, and is succeeded 

 by a narrow and parallel deposit of ferruginous sand*, shghtly indurated, 

 the surface of which, if we may draw any inference from some insulated 

 beds of gravel that occur on the highest points, must once have pre- 

 sented an uniform extent of table landf." 



Organic Eemains. 



The fossils of the blue chalk marl, like those of other argillaceous 

 strata, are remarkable for their beauty, the pearly covering of the shells 

 being in most instances preserved. 



1. Vegetables. Wood is stated by Mr. Phillips to occur at Folkestone; 

 but I have not observed any decided remains of vegetables in the blue 

 marl of this part of Sussex. 



In the malm rock near Amberley, the Kev. J. Hanley has recently dis- 

 covered the remains of a large tree, in wliich the ligneous structure of the 

 original is very distinctly exhibited:]:. 



2. Turbinolia Konigi, tab. xix. fig. 22 and 24. 



Inversely conical, aperture circular, divided by numerous perpendicular 

 lamellae, radiating from the axis to the circumference ; axis simple ; margin 

 crenulated ; external surface longitudinally striated ; striae from 25 to 30, 

 distinct, prominent ; base convex. 



This elegant little coral is from 0-4 to 0*5 inch in diameter, and about 

 0-3 inch high ; the lamellae are numerous, generally exceeding 50 ; the 

 striae on the external surface are distinct, proceeding from the base to the 

 margin, where they unite with the lamellae alternately. 



This fossil occurs in every locality of the blue marl near Lewes, and 

 appears to be one of its most characteristic productions. It has also been 



* This bed belongs to the green sand, and has been already described in the account of 

 the strata at Parham Park. 



t Extract of a letter from J. Hawkins, Esq. Bignor Park. 

 j On the authority of J. Hawkins, Esq. F. R. S. 



