pL, 



^ 



ft^ 



valley at St. David's Hill, sands almost en- 

 tirely replace the clays of the Katesgrove 

 pit (PL I. Diag. A, Loc. sect. 6). 



A feature of considerable interest con- 

 nected with this series was exhibited in the 

 railway cutting for the Newbury branch 

 line through the hill west of and adjoining 

 Reading. Under the mottled clays there 

 were a few feet of sand, and then a local 

 and lenticular mass of very finely laminated 

 light greenish clay abounding, in places, 

 with the most beautifully preserved impres- 

 sions of plants. Beneath this bed were 

 strata of yellow sand succeeded by the bed 

 of green sand with the Ostrea Bellovacina. 

 I give this section in full, both to show 

 these points and also as a good instance of 

 the irregular deposition of the mottled clay 

 series. (For the plants see PI. IV.) 



Feet. 

 1. Ochreous flint-gravel, varies greatly in thick- 

 ness — averages 10 



b. Mottled red and light bluish grey clay pass- 



ing down into slightly laminated light 

 grey clays 20 



c. Laminated yellow sands 2 



d. Thin layers of light grey and greenish clays 



more or less sandy; some of the seams con- 

 sist of a very pure and fine clay slightly 

 mottled .with a tinge of red. Extremely 

 perfect and very numerous impressions of 

 leaves are found in this bed 4 



e. Fine yellow sand with shght false stratifica- 



tion. Ferruginous clayey sand in patches 



— soft ferruginous casts of wood 8 



a. Green sand with a band of Ostrea Bellova- 

 cina aty _^ 



46 

 4. Chalk, with tubular surface-perforations 

 filled with green sand aty 6 



East of Reading the cutting of the Great 

 Western Railway at Sonning Hill afforded 

 an excellent section of the Reading series 

 and of the Basement-bed of the London 

 Clay. Here, the sands which, between 

 Newbury and Reading, are often as fully 

 developed as the mottled clays, disappear 

 almost entirely, and pass into or are re- 

 placed by mottled clays. This section also 

 shows the peculiar waved and irregular 

 lines of bedding of these strata, which here 

 as usual contain no organic remains*. 



* The workmen however described to me a speci- 

 men which, from their account, would appear to 

 have been the head or jaw of a fish that they had 

 found in tlie middle of this series. The Basement- 

 bed of theLondon Clay,whichcaps the hill.abounds 

 in well-preserved fossils. 



