164 Dr. R. P. Cotton on the Pliocene Deposits 



been kindly sent me by Edmund Getty, Esq. The wood itself 

 is perfectly sound, but the tree is split and rived in the direction 

 of the grain in some places almost into shreds by the boring 

 powers of the Teredo. 



XVII. — On the Pliocene Deposits of the Valley of the Thames at 

 Ilford. By Richard Payne Cotton, M.D. 



The tertiary deposits bordering on the Thames appear to be 

 composed of materials of the same general characters, variously 

 arranged, but formed under the same physical circumstances. 

 The formation may be well seen at Brentford, Ilford, Grays and 

 Erith, where beds of gravel will be found resting upon sands of 

 various colours, sandy loam and clays, abounding in remains of 

 mammalia and freshwater shells*. The following description re- 

 fers to two cuttings in brick-fields at Ilford, one on the north of 

 the London road, belonging to Mr. Curtis, another on the south 

 of the same road, and the west of the Barking lane, the property 

 of Mr. Kilverton. In the former we observe — 



feet. 



Vegetable soil with gravel 2 



Coarse gravel 2 



Coarse yellow sand, stratified 4 



Brick earth of various shades of brown, regularly stratified with 1 _ 



nodules of carbonate of lime (race) and a few bones J 



Light brown brick earth, interstratified with layers of sand, and 1 .. 



full of bones / 



Thin veins of fine sand of shades of yellow and brown irregularly "I „ 



waved / 



Coarse gravel and sand. [ — 



18 

 In the latter the arrangement is as follows : — 



feet. 



Vegetable soil with gravel 2 



Coarse gravel and sand stratified 3 



Brick earth of shades of brown, stratified 6 



Brick earth of a light brown with wavy veins of sand, calcareous 1 ~ 



nodules (race) and bones J 



Layers of brown and yellow sand, waved, containing in its upper ) . 



part an abundance of bones / 



Fine yellow and white sand, with freshwater shells 2 



Coarse gravel with water. — 



19 

 The stratification of the clays is generally regular and hori- 

 zontal, the layers however frequently thin out or expand, but the 

 veins of sand are irregular and waved, so that the surface of the 

 cutting, from the changing thickness of the strata, varies extremely 



* A list of the shells occurring in these mammaliferous deposits has been 

 given by Mr. J. Morris in the ' Magazine of Natural History/ vol. ii. p. 544. 

 —Ed. 



