l\Q STRATA IN THE NKIGHBOURIIOOD OF L01«D0!f< 



In the French stratum there occur, 



Fo'sils in ihe Two lituolUes. No species of this genus is noticed as 



French harin"- been seen in our English chalk. But research has 



stratum. " , ■ , , 



not been made with the necessary precision. 



Three veriniculites. The fossil figured Org. Rem. vol. 



Ill, pi. VII, fig. 11, was considered as a vermiculite, until 



by removal of the chalk, and opening differenti^pecimens, it 



was found to be a chambered and an adherent shell. Should 



these gentlemen not have perceived these circumstances in 



the sj)ecimens they met with, they would certainly regard 



this fossil as a vermiculite. It must also be observed, that, 



from the different forms in which the spiral part is disposed, 



its division into two or three species might be authorised. 



/>W(?/nMi/e5. These, according to Mr. De France, are dif- 

 ferent from those which accompany the ammonites of the 

 compact limestone. The helemnites of onr chalk are smaller 

 than those of the limestone, beside which they are different 

 inform, being nai-rovver and more elongated. But Mr. De' 

 France may also have confounded with them the spines of 

 the echinus, which so closely resembles the belemnite : if 

 that gentlemen should not have met with perfect specimens, 

 he might not be able to remark the difference between these 

 two fossils. The characters, which he has noticed, are how- 

 ever sufficient to lead to the belief of a correspondence 

 between the French and English fossils. 



Fragments of a thick shell of a fibrous structure. The 

 doubts expressed respecting the nature of this shell, and 

 the observations made with regard to it, offer another strong 

 point of agreement between the shellsof the two strata. The, 

 shell here alluded to is most probably that represented Org, 

 Hem. Ill, pi. V,fig. 3 ; the structure of which agrees exactly 

 with that mentioned as found in the French stratum of clialk. 

 That shell is however described as being of a tubular form; . 

 it is therefore rigiit to observe, that fossil pinnce do some- 

 times possess this peculiar structure. 



A muscle. No instance appears in which any shell of 

 this genus has been found in our chalk. 



Two oysters. The Kentish chalk-pits yield at least three 

 species of this genus. One of them bearing very much the 

 form and appearance of ostrea edulis, but being only about 



>. a fourth 



