56 Geological Society : Mr. Pearce on the 



lage of Biarritz, near which there is an excellent coast section. The 

 sands and clays have nearly thinned off before reaching the cliffs 

 which rise from beneath the dunes, about a mile and a half to the 

 north-east of the village, and vary in height from 20 to 80 feet. In 

 a small bay called the Chambre d'Amour the beds are well seen, con- 

 sisting of strata of sandy argillaceous limestone, from a few inches 

 to five or six feet in thickness, all containing fossils in greater or 

 less abundance. Several faults occur between the first rise of the 

 strata and the village, by which the upper beds are repeatedly 

 thrown to the level of the shore. The organic remains vary con- 

 siderably in the several beds throughout the series, but Lenticulites 

 and Nummulites characterize the whole ; corals are numerous, but 

 shells more rare. In the disturbed strata at Biarritz all the Echino- 

 dermata, which are very numerous, have been found. 



Among the fossils at the Chambre d'Amour are, besides the fora- 

 minifera before mentioned and numerous corals, the following mol- 

 lusca : — Pholadomya margaritacea, Venus transversa, Pinna marga- 

 ritacea, Spondylus radula, Gryphcea vesicularis ? Pecten arcuatus 

 and tripartitus, Solcn strigilatus, and Teredo articulata ; also Turri- 

 tella carinifera, Pyrula nexilis and Triton appeninum. Ditrupa subulata 

 and several Serpulee accompany them. 



Passing the disturbed beds, strata of calcareous rock, more or less 

 argillaceous or arenaceous, alternating with a bluish clay or marl, 

 rise regularly at an angle of 60° or 70°, and are continuous for 

 nearly a mile, forming cliffs above 120 feet high. The uppermost 

 of these beds is chiefly composed of Nummulites and Lenticulites, the 

 arenaceous strata contain numerous and well-preserved corals, the 

 species of which have not as yet been determined, though referred 

 by D'Archiac to cretaceous forms. In the lower beds the best iden- 

 tified tertiary forms were found mingled with species hitherto re- 

 garded as cretaceous, such as Serpula ampullacea and S. rotula. 

 Among the mollusca occurred Spondylus rarispina, Ostrcea spathu- 

 lata, Dentalium grande, Turritella carinifera, Scalaria semicostata and 

 acuta, Cerithium turritellattim and cinctum, with several undetermined 

 species of various genera. 



The cliffs cease for a quarter of a mile, being terminated by a 

 fault, when the strata again rise at a small angle in the same direc- 

 tion. Their mineralogical character however is different, as they 

 consist of a marly light- coloured limestone, abounding in fossils 

 which are mostly distinct from those of the preceding beds, with 

 the exception of the corals. The protrusion of igneous rocks has 

 changed this limestone in places into a hard crystalline marble 

 or dolomite. In this part of the series were found Terebratula bisi- 

 nuata and striatula. Another fault throws these beds beneath the 

 shore, and at an interval of a few hundred yards they are succeeded 

 by a series of cretaceous beds resembling chalk marl, the general 

 inclination and direction of which, on account of frequent disturb- 

 ances, are difficult to determine, but appear to be the same with 

 the last-mentioned strata. The cliffs formed by the cretaceous 

 strata rise to a height of from 50 to 150 feet. Three or four species 



