1866.] WHITAKER LOWER LOl^DON TEETIAEIES. 433 



and Mull are also in this list, together with beds in other parts of 

 the world. 



It should be understood that I do not venture to assert that the 

 iron-sands of Paddlesworth &c. are Eocene, but only suggest that, 

 in the absence of good palseontological evidence, one might look on 

 them as of that age. The great difficulty in the way of classing 

 them with any of the old Tertiary beds of the neighbourhood seems 

 to be, that their fossils as a group are not like those of the latter, 

 but (as far as the Eocene species are concerned) seem rather to be 

 more allied to those of our Bracklesham beds, or perhaps of some of 

 the Tertiaries of the Continent. I can see no difference in the con- 

 dition of the fossils which would warrant the inference that some 

 have been derived from older beds : those that have been referred to 

 Crag species are in just the same state as the Eocene forms. 



Eor the present, therefore, it would perhaps be well not to com- 

 mit ourselves to any theory ; but should clearer evidence of the Crag 

 age of the fossils be given, either by the finding of better specimens 

 or by the further examination of those already found, I shall be 

 glad to take Mr. Prestwich's view ; and if this note on the subject 

 should be the means of bringing forward such evidence, by drawing 

 further attention to the question, its author will be as well pleased 

 as if he could himself make out the age of the doubtful beds. 



I take this chance of putting right a mistake made in a former 

 paper * (where, by the way, I adopted the Crag theory) in saying 

 that Mr. Godwin-Austen classed some outliers of sand on the Chalk- 

 hills of Surrey as Lower Bagshot. He has always looked on them, 

 and on the Kentish outliers too, as Lower Eocene, as also has my 

 colleague Mr. Bristowf. 



§ 8. Conclusion-. 



Prom what has been said above, and from a study of the sec- 

 tions in Plate XXIL, we may gather the following facts amongst 

 others : — 



1. That the base-bed («) is the only constant part of the Thanet 

 Beds. 



2. That the higher and fossil-bearing parts of that series (d, e) 

 occur only in the east, which partly explains why it is often 

 very hard to separate the Thanet Beds from the overlying series in 

 the eastern part of Kent, whilst the division is well-marked west- 

 ward ; and that the unfossiliferous sand (c) thins out on the east, 

 so that the Thanet Beds near Canterbury may be a different thing 

 from the Thanet Beds between London and Bochester. 



; 3. That the bottom-bed (1) is also constant, except in the far east. 



4. That above this last there is always a sand (2), a pebble- 

 bed (2 a), or a mottled clay (2 6), which replace one another. 



5. That one very thin bed (3) in the middle of the Woolwich 



* Quart. Journ. Geol. Soc, vol. xviii. p. 273. 

 t See his note on the subject at p. 553. 



