SKETCH OF THE GEOLOGY OF BIARRITZ. 
475 
cliff begins a long rectilineal escarpment, which extends to the * Port 
des Basques,' marked out with great regularity to the N.N.E., for the 
distance of rather more than a mile. Opposite the point where this 
cliff begins, there rises in the sea a rock much more considerable 
than those we have hitherto met with, and which is designated by 
M. Thorent the ' Kocher du Goulet :' it is formed of grey-blue lime- 
stone, tolerably hard, and worked as building-stone ; it dips to the 
N.N.E., and encloses a great quantity of fossils." (This rock has been 
so much worked for building that it is below high -water mark, 1861.) 
" The cliff itself, throughout its whole extent, presents a very uniform 
appearance. It consists exclusively of alternate beds of bluish clay 
and soft limestone of the same colour, dipping regularly to the N.E. at 
an angle of about 40° or 45"^. The only fossil found there is the 
Serpula sinrulceay (As you approach the Port des Basques, the 
beds become richer. On the shore, imbedded in the rock, I have 
found several varieties of shells, and also a good deal of wood.) 
"This long clay cliff terminates abruptly at the Port des Basques 
against the promontory of Biarritz. 
" Here begins a new system of deposits, harder than those which we 
have hitherto described, and to this circumstance is due the singular 
aspect of the whole of this mass of rock, fantastically worn by the 
sea. * * * It is composed of yellow arenaceous limestones to- 
wards the south, intermingled with beds of arenaceous limestone of a 
bluish shade, which, advancing northward, become more and more 
abundant. These limestones enclose an enormous quantity of small 
nummulites {N. intermedia), which of themselves almost form small 
beds ; the Eupatagus oniatus is also sufficiently plentiful ; finally, 
round the ' roche percee,' the Scutella suhtetragona is frequently met 
with ; this fossil has, no doubt erroneously, been stated to be found 
in the Dax beds. * * 
" In the regular strata, rolled pebbles of hard grey subsaccharoid 
limestone, and also of black flint, may be frequently observed ; 
they are the debris of the siliceous limestone of the chalk period, 
similar to those in the escarpment of Bidart, and which must have 
existed as rocks on the shore of the sea in which the nummulitic beds 
were in process of formation. 
" The whole strata which form the mass of the rock at Biarritz are 
overlaid by a very modern deposit of yellow sand, which on the 
Attalay attains the thickness of at least fifteen or twenty yards. 
(This modern deposit beyond the Attalay, beneath the Empress's 
' chapel, contains wood and great masses of vegetable matter.) 
" Beyond the point of Biarritz begins the ' Cote du Moulin,' bor- 
dered at first by little escarpments, surmounted by some sand-hills. 
These escarpments are formed of a very sandy bluish limestone, with 
some yellowish bands containing an abundance of the Nummulina 
Biarritziana,' also the Eupatagus ornatus, the Schizaster rimosus, &c. 
Low sand-hills occupy the space beyond, for a distance of 600 or 650 
yards, after which follows a steep cliff, twenty-five or thirty yards high, 
composed of bluish sandy limestones, with some yellow bands, con- 
