EXPOSURE OF LONDON-CLAY AT CHINGFORD ESSEX. 75 
(3) Brown loam.2ft Gin. Water is thrown out at the junction 
of this with :— 
( 4 ) Tenacious brown clay, to bottom of working.4 to 5 ft. 
Strata 1 to 3 (which are not separated from each other by 
any hard and fast lines) represent the Claygate Beds, or “ passage 
beds ” between the London Clay and the Bagshot sands. Stratum 
4, at the bottom of the pit, marks the highest part of the London 
Clay proper. 
More recently, a brickyard has been opened on the side of 
Park Hill, Chingford, a few hundred yards to the south-east 
of the section just described. In autumn, 1914. the section here 
showed (in descending order) :— 
Surface, about 230 ft. O.D. 
(1) Tenacious brown clay, with fossiliferous septaria.3 ft. 
(2) Brown loamy clay, sandy in places.3 ft. 
(3) Tenacious brown clay .3 ft Gin. 
(4) Brown loamy clay with streaks of sand .2 ft., to bottom of 
working. 
The section is by no means a large one, and it is quite possible 
that the sandy beds 2 and 4 are only portions <pf large lenticular 
masses. The surface of the ground in this pit is about 
15ft. below the bottom of the Pole Hill section, so it will be seen 
that the fossiliferous septaria, occurring as they do but a little 
way below the base of the Claygate Beds, and just above two 
distinctly sandy seams, occupy a position very near the top of 
the London Clay. 
Many of the septaria have a distinct element of sand in their 
composition and exhibit traces of stratification. Small crystals 
of selenite are abundant in the clay, while radiating crystals 
of Barytes are found, in cavities on top of the fibrous calcite 
which lines the cracks in the septaria. 
The septaria in this Park Hill pit. contain numerous fossils. 
These have been kindly named by Mr. E. T. Newton, F.R.S., 
F.G.S., and the following is a list of the species obtained, those 
which occur plentifully being marked with an asterisk (*) :— 
Lamellibranchia. 
Avicula media (Sby.) 
„ ,, papyracea 
Pecten corneus 
Pinna, sp. 
Modiola simplex (Sby.) 
* „ „ elegans (Sby.) 
,, ,, lubicola (S. Wood) 
*Axinea ( Pectunculus) decussatus 
(Sby.) 
