THE FOSSIL FORAMINIFERA OF THE 



BLUE MARL, COTE DES BASQUES, 



BIARRITZ. 



The Blue Marl of Biarritz forms a cliff stretching for nearly 

 three-quarters of a mile in a direction from N.N.E. to S.S.W., 

 and above the Bathing Establishment at its northern extremity 

 where it abuts on the promontory of La Talaye it attains a 

 height of about 135 feet. This height is maintained for about 

 two thirds of its length, when it commences to decrease in 

 altitude finally dying away at the valley of Chabiague to the 

 south. At the northern section where the cliff is most precipi- 

 tous, and until a short distance past the Villa Notre Dame, the 

 beds are inclined at an angle of about 40 , dipping towards the 

 north. This angle afterwards gradually decreases and at the 

 villa called TErmitage is from io° to 15 only. At l'Ermitage a 

 hollow in the upper part of the cliff is filled with red and yellow 

 sands and gravels. In the upper part of the Marl hard layers 

 are few and thin, these beds are wanting in the middle portion 

 of the marl and are replaced by sparsely distributed large 

 concretionary nodules of hardened marl of a light grey colour, 

 tinged brown where weathered, a colouration no doubt due to 

 iron oxide. In the southern section, commencing south of 

 l'Ermitage, hard beds of limestone are numerous, and the marl 

 itself, except at the extreme base of the cliff is more sandy. In 

 some portions these hard beds are almost horizontal. 



The strata above described have been placed by geologists 

 in the Middle Eocene series, and are believed to be contem- 

 porary with the Bartonian beds of England. They are referred 

 to as the Orbitoidal or Serpula spirilla a Marls. 



Having written thus briefly of the physical features of the 

 region of the Blue Marls I will now deal with their micro- 

 zoological contents. The collection of Foraminifera which is 

 about to be described was obtained at three different times. In 

 the spring of 1893 a sample of marl having been taken with 

 a view to a search for Foraminifera, the results were so encour- 

 aging that a further examination was decided upon. A second 

 visit was made to Biarritz in the autumn of the same year, and 

 a systematic series of gatherings taken. It was at first thought 



