PRESTWICH — WOOLWICH AND READING SERIES. 



HI 



Drift 



London clay 



I. Basement-bed 

 of the London 

 clay (for the 

 fossils of this 

 division, see 

 Journ. Geol. 

 Soc. vol. vi. 

 p. 265). 



. Woolwich and 

 Reading Series. 



(PI. I. Diag. A, Loc. sect. 43.) 



Feet. 



Ochreous flint gravel 4 to 6 



Tenacious brown and bluish clay, with few or 



no fossils 10 to 15 



b. Fine light-coloured siliceous sands, with oc- 



casional large tabular masses of sand- 

 stone, white, grey, ferruginous, and brick- 

 red. Lenticular twin-crystals of sulphate 

 of lime, and small soft concretionary 

 lumps of the black oxide of iron, common. 

 Seams of flint-pebbles of occasional oc- 

 currence. False stratification of the sands 

 not unccmmon. Fossils common, occa- 

 sionally dispersed in the sands, but more 

 commonly in irregular patches, and in the 

 sandstone blocks 22 



a. A layer of flint-pebbles in sand, (yellow, 



green, and ferruginous,) often concreted ; 

 abounds in organic remains 1 to 2 



c. Argillaceous green sand, passing down into 



yellowish sand with less clay 12 



b. Dark grey argillaceous sand, full of small 



ferruginous sandy tubular concretions and 

 lumps, passes down into a brownish sandy 

 clay, and then into a light greenish-grey 

 clayey sand, with a very few small flint 

 pebbles. Nodules and lumps of iron py- 

 rites, with coarse gi'een sand and very 

 small quartz pebbles, are common. Wood 

 in fragments and pieces in the state of 

 lignite are of frequent occurrence. A very 

 few teeth and palates of Fishes are found. 7 



a. Light ash-green and yellow sands with casts 

 of shells, passing down into a coarser gi"een 

 sand, near the base of which a thin band 

 of very coarse and bright green sand, some- 

 times concreted and abounding in silici- 

 fied shells, occurs 9 



Yellow, greenish, and grey fossiliferous sands. 

 These only just appear at this spot. 



III. Thanet Sands. 



(Journ. vol.viii. 



p. 262.) 



The strata a, b, and c, ii, of 



Woolvpich and Reading series, 

 a grovip of organic remains, 

 species : — 



Ampullaria subdepi'essa, Mor. 



Cardium Laytoni, Mor. 



Plumsteadiense, Sow. 



Corbula Regulbiensis, Mor. 



Cucullffia crassatina. Lam. 



Cyprina Morrisii, Sow. 



Scutellaria, Desh. 



Cytherea Bellovacina, Desh. 



Fragments and pieces of wood in the state of hgnite, frequently 

 bored by the Teredo, are not uncommon, and in an ironstone concre- 

 tion I found a fine specimen of a Fir Cone (PI. III. fig. 4). This 

 bed also contains, nearer to the Reculvers, specimens of silicified wood 



this section I take to represent the 



In its lower bed " « " there is 



consisting of the following marine 



Dentalium. 



Glycimeris Rutupiensis, Mor. 



Pectunculus terebratularis. Lam. 



Sanguinolaria Edwardsii, Sow. 



Teredo antenautse. Sow. 



Thracia oblata, Sov). ? 



Teeth of Lamna. 



