212 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



have assumed in East Kent ; at Pegwell Bay, for example, many of 

 the lower beds are unusually argillaceous, and of a dark grey colour — 

 some are fossiliferous, others without a trace of a fossil. M. Meugy 

 states that the strata in many places contain marine shells, but, with 

 one exception (Ci/prina planata [Moiinsiil^), he gives the genera 

 only, and not the species. Sir Charles Lyell^ however, who has also 

 examined part of this district, states that at Carvin near Lille the 

 Cyprina Mon'isii abounds and that imperfect casts of a Turritellay 

 Area, and Corbula occur*. Further, these beds are considered by 

 M. Meugy as the continuation of the Lower Landenian series 

 of Belgium. 



In Belgium this character of these beds is but little modified ; but 

 the fossils have been better determined, and form a fauna closely 

 agreeing with that of the Thanet Sands. I have found at Tournay 

 and Mons, fossils which I have identified with those of East Kent, 

 though they are not quite so numerous or varied. The occurrence, 

 however, amongst these few of such species as the 



Astarte tenera, Mor. {A.incBquilatera, Nyst.) Pholadomya cuneata, Sow. 



CucuUaea crassatina, Lam. Koniuckii, Nyst. 



Paaopaea granulata, Mor. Cyprina Morrisii, Sow. 



combined with the general resemblance in mineral characters, 

 development, and superposition, confirms me in the belief that the 

 same deposit occupies the same position at the base of the Tertiary 

 series in both countriesf . M. Duraont, from an examination of the 

 lithological structure of the beds overlying the Chalk at Chiselhurst 

 and "Woolwich, had before come to the conclusion that these Lower 

 Tertiary Sands are of the same age as those in Belgium — that they 

 are the equivalents of the lower division of his Landenian system. 



I have not been able satisfactorily to recognise the Thanet Sands 

 in the Paris Tertiary district ; but, from the frequent difficulty, even in 

 this country, of distinguishing this division from the one next above it, 

 — for the lithological characters of the two are often almost identical, 

 — it would be impossible to say, in the absence of sufficient organic 

 remains, whether some portion of the Glauconie inferieure of M. D' Ar- 

 chiac should not be referred to the Thanet Sands period. This 

 Glauconite forms the base of the Tertiary series in the more northern 

 portion of the Paris basin, and detached outliers of it are common on 

 the chalk hills which separate the Paris and Belgian Tertiary areas. 

 It rarely exceeds 20 to 30 feet in thickness. M. D'Archiac notices 

 the constancy of its characters and the rarity of organic remains, 

 the only fossils he has been able to detect being casts of some marine 

 bivalves, referred to the Cyprina Scutellaria, Desh., Serpula, casts of 

 a species of Sponge (Sponyia nidus-avis, D'Arch.), bones of JEmydes 



* Quart. Journ. Geoi. Soc. vol. viii. p. 360. 



t M. Omalius d'Halloy in his last work, with which I have but just become 

 acquainted, gives a corrected list of these fossils amounting to 14 species. Of 

 these, besides those quoted in the text, the Nucula fragilis also occurs in the 

 Thanet Sands, the Scalaria Dumontiana of Nyst is probably the S. BowerbanMi of 

 Morris, and the PanopcBa intermedia, Sow., the P. granulata, Mor. The Leda, 

 Cytherea, Area, Pinna, and Modiola will also, I think, prove to be species common 

 to both countries. The list of fossils from these beds is, however, yet far from 

 complete. — J. P., Jun., April 1855. 



