Woods of North-East Kent . 885 
The following plants are generally found on the more stony soils : — 
Senecio sylvaticus , L. Air a flexuosa, L. 
Teucrium Scorodonia , L. 
The following are found, generally in small quantities, on soils in the 
vicinity of the Chalk:— 
Hypericum hirsutum , L. Euphorbia amygdaloides , L. 
Verbascum Thapsus , L. 
In addition to the above a small number of ruderal plants, weeds, &c., 
are found. These are present in greatest quantity during the first two 
years after felling and disappear later. Annual, biennial, and perennial 
plants are included in the list:— 
Viola tricolor , L. Solarium nigrum , L. 
Heracleum Sphondylium , L. Polygonum aviculare, L. 
Senecio vulgaris , L. Polygonum Convolvulus , L. 
Taraxacum officinale , Weber. 
The great abundance of Mnium hornum , L., in some of the Chestnut 
coppices of the Thanet Sand has already been referred to. This is fre¬ 
quently associated with Leucobryumglaucum, Schp., Poly trichum attenuatum , 
Menz., and Dicranum montanum , Hed. On the drier, more stony soils, 
Mnium hornum is partially replaced by Polytrichum juniperinum , Willd., 
and Dicranella heteromalla , Schp. Catharinea undulata (L.), Web. Mohr., 
occurs abundantly on the sandy loam without pebbles, associated in the 
damper spots with Pellia epiphylla , L.; both these species are absent on 
the drier soils. Georgia pellucida (L.), Rabenh., and Orthopyxis androgyna 
(L.), Beauv., are generally distributed in small quantities; neither of these 
species has been discovered on the Chalk or Clay with Flints. Isopterygium 
depressum (Bruch), Mitt., is usually present. Diplophyllum albicans , L., 
occurs commonly on banks and cuttings associated with Jungermannia 
ventricosa , Dicks., and Lepidozia reptans , L. 
The Woolwich and Reading Series. 
The Woolwich and Reading formation is made up of beds of coarse 
sands and gravels alternating with occasional thin beds of clay. In con¬ 
sequence the character of the soil produced varies considerably in different 
situations, the gravels and sands giving rise to light sandy loam in which 
the drainage is rapid, while the bands of clay produce heavy, badly-drained 
soils. In all these soils the amount of calcium carbonate is very small. 
In an analysis published by Hall and Russell ( 7 ) the percentage of lime is 
given as o-i, a proportion lower than that found in the majority of the soils 
