PRESTWICH — BRITISH AND FOREIGN TERTIARIES. 241 



EXPLANATION OF PLATE VIIL 



Section 1 is drawn from the nearest points in England and in French 

 Flanders, where all the series beneath the Caleairc grossier zone inelusive 

 occur. The depth and [)()sition of the strata along this line are })rove(l at 

 the following points by local sections of railways, wells, and elitfs, which 

 have already been described. 



Goldsworth Hill, Chobham Place, "I See Quart. Journ. Geol. Soc. vol. iii. pp. 382, 



Woking Com., Chobham Ridges j 384. 



Maryland Point, Stratford Ibid. vol. vi. p. 2G2. 



Claremont, Mortlakc, Kingston, 1 



Kensington, Haddington, Horn- l Ibid. vol. x. pp. 96, 144-7. 



sey, lloxton J 



Hampstead, Langdon Hill, Hay- 1 ., , 



leigb, Southend, Heme Bay / ^^''^- ^^^- ^- PP' ^"^ '* 



Upminster Proc. Geol. Soc. vol, iii. p. 132. 



Heme Hay, Ricbborough Quart. Journ. Geol. Soc. vol. viii. pp.239, 251. 



Chislet, between Home Bay and It.., , . , , , 

 1,.,, , ^ >■ Ibid. vol. XI. p. 11 L 



Kichborough J '■ 



Calais * TheWatcr-bearingStrataof London, 'p. 208. 



y^ J r Quart. Journ. Geol. Soc vol. viii. p. 32 4, and 



\ Essai sur la Fland. Fran9.,pp. 156-169, 



The heights of the principal hills in this country I have determined roughly 

 by the aneroid barometer ; those in Flanders are taken from the French 

 Ordnance-maps. 



Section 2 is a continuation of Section 1 prolonged southward to that 

 nearest portion of the Paris basin where a comj)lete development of all the 

 beds forming the " Sables inferieurs " of M. d'Archiac occurs in connec- 

 tion with the " Calcaire grossier " group. In this second section and part 

 of the first, as I have not had leisure to visit all the French localities, 

 several of the main geological features arc derived from the local descriptions 

 of Sir Charles Lyell and M, Meugy in Flanders, of M. Buteux in the 

 Somme, and M. Graves in the Oise ; whilst the general configuration of 

 the country is taken a})proximately from the admirable French Ordnance- 

 maps, which furnish us with levels both of hills and river -courses, that 

 our otherwise excellent ma})S are entirely deficient in. 



The following are the references to sections on this line : — 



Bailleul, p, 153; Armentieres, p. 152; Seelin, p. 107; Douai, p. 106; 

 see also map and sections ; — Meugy, " Essai de Geologic pratique sur la 

 Flandre Fran^aise," 1852. 



Mons-en-Pevele ; — Lyell, Quart. Journ. Geol. Soc. vol. viii. p. 359. 



Davenescourt and Ilangest, north of Montdidier, p. 45 ; — Buteux, " Es- 

 quisse Geologique du Departement de la Somme," 1849. 



Coivrel, pp. 184, 244; Agnetz, pp, 248, 370, 4f)3 ; St, Felix, pp. 2.9.9, 

 372; — " Essai sur la Topogra])hie Geognostique du Departement de I'Oise." 



The neighbourhood of Noailles is sketched chiefly from my own obser- 

 vations. 



The paper of M. Elie de Beaumont in the ' Mcinoires de la Societe 

 Geologique de France,' vol. i, p. 107, has aided me in the general features. 

 The valuable geological maps of M. Elie de Beaumont and M, Uuraont have 

 also been of material assistance. 



VOL. XI. PART I. S 



