■emarkable 



ijg STRATA IV THE NEIGHBOURHOOD OF LOMI>dK. 



««R8es all the other rbaraclers of ammonites, the spiral coil 

 is disposed in 3 form rather approaching to that of the oval 

 than the circle*. 



]» another fos&il of this stratum a still more extraordinary 

 deviation exists. This fossil possesses the concaraerations 

 and the foliaceous sutures of the cornu ammonia; hot, in- 

 stead o4" being spirally coiled, it has its ends turned toward 

 e-ach other, somewhat in the form of a canoe. This peculiar 

 form has led to the placing of this fossil under a separate 

 genus, which has been named scaphitesf. 

 Extent ofthls Of the extent of this stratum no correct account has been 

 gtren; but there is sufficient reason for believing, that it 

 accompanies the otlier chalk in its range through this island. 

 It also appears, that its peculiar fossils exist in it at very 

 considerable distances. Thus the oval ammonite, which is 

 found in the Sussex hills, likewise occurs in the hard chalk 

 of Wiltshire; and the scapkifes, another inhabitant of the 

 Sussex hills, has also been discovered in JDorsetshire. 



Thesttat* ^" comparing the preceding sketch with the Essay on the 



aboreth* Mineralogical Geography of the neighbourhood of Paris, 

 knd dSr '*^" ^ Messrs. Cuvier and Brongniart, some important varia^ 

 from tho",ein tions will be perceived between the strata found above the 

 France^ ^^j^jj^ -^^ ^j^j^. ^^i^^^ yj,j ■^^^ France. In France, the strata 



above the chalk differ both in number and quality from 

 those, which have been hitherto observed in a similar situa-. 

 tiou in England. In France too, several strata of sand and 

 sandstones exist above the strata of th/e gravel formation, 

 which in this island appear to be highest. 

 Attfrnpt to The first of these differences appear to result chiefly from 



arrount for ^}^^, existence of numerous beds or patches, the formation of 

 which must have depended on certain local circumstances, 

 such as the existence of fresh or salt water l«kes, at the pe* 

 riod of the drying up of ^ former ocean ; the different che- 

 mical combiuatiooft, which might thence have taken place; 

 &c. But the occurrence of such variations can hardly be 

 considered as interrupting the continuity of the stratifi- 



coiion. 



* Organic Remains, vol- 111, pi. IX, fig. &, 



t Organic Remains, yoI. HI, pj, X, fig. 10 and 11. 



Indeed 



