STRATA IN THE NEIGHBOURHOOD OF LONDON. SI 



Bot although this clay stratum contains fossils of a much This stratum, 

 older date than those of the gravel stratum, it possesses tbun^ihe fo^ 

 other marks, which agree with its position in showing, that nier,yei mo- 

 it is of comparatively modern formation. It includes none ^ . , 

 of the remains of any of the lost fossils, such as the cornu io°jfo„*j"L^ 

 ammonis, encrinitcs, &c. Mr. Jacobs indeed speaks of one it. 

 imperfect specimen oi belemnites and of astroitce having been 

 found, but at the same time as being very uncommon ; Mr. 

 Brander however does not appear to have met with any of 

 these older fossils ; nor have any of them been discovered either 

 at Kevv or at Highgate. Hence it seems reasonable to con- 

 clude, that the single imperfect belemnite and the few as- 

 troitae were not inhabitants of the sea at the period when 

 this stratum was deposited, but were washed out of some of 

 the more ancient strata, and lodged by accident in the bed 

 where they were found*. 



The quantity of fruit or ligntous seed vessels and berries, 700 specimens 

 which has been found in this stratum at Shepey, is prodi- o^*^*"** ''*""'*' 

 gious, Mr. Francis Crow, of Fevorsham, has procured from 

 this fertile spot a very large collection; and, by carefully 

 comparing each individual specimen by their internal as well 

 as their external appearance, he has been enabled to select 

 seven hundred specimens, none of which are duplicates, 

 and very few agree with any known seed vessels. These 

 vegetable remains have also been found on the opposite Es- 

 sex shore, but in very small numbers. They have also been 

 met with in that part of the stratum, which has been exa- 

 mined at Kew. At Highgate and at Shepey a resinous PecuUar resin, 

 matter, highly inflammable, of a darkish ^rowa colour, and °"' matter, 

 yielding, on friction, a peculiar odour, has also been found. 

 This substance has been conjectured, to exist in an un* 

 altered state; and this indeed seems to be the fact from its 

 resinous fracture: but it must be observed, on the other 



* It appears to be necessary to guard against two sonrces of errour. Two lourcei^f 

 while appropriating foisilsto their respective strata: one is thccircum- ^"®"'* 

 stance here alluded to, where the fossils of a preexistcnt stratum have 

 been washed out by the waters while depositing a more recent stratum : 

 the othor is where, at the line of junction of two strata, the animals of 

 the one are found within the borders of the other stratum; a circum- 

 stance by no means difficult to he conceived or explained. 



E ^> haud, 



