154 M. Chakbaut on the 



bers, situated in a north and south direction, and com- 

 municating with each other by passages of different dimen- 

 sions. 



i The river la Seiile, flowing at the bottom of the valley of 

 Voiteur, rushes out of a cave perfectly resembling the last. 



If it be observed that the latter is situated precisely on 

 the north of the former, that is to say, in the direction in 

 which the waters of the sea have retired, it will appear very 

 probable that the two caves communicate with each other, 

 and form but one. 



A kind of subterranean lake prevents the verification of 

 this conjecture. 



It is very probable that the rocks of Baume, mentioned 

 above, form a continuance of the cavern of la Seiile, and that 

 they have fallen down much later than the other excavations 

 of the valley of Voiteur. 



- The calcareous mass of this formation is traversed through- 

 out its height by very numerous clefts ~, it follows that the 

 rain waters are not retained on the surface, they infiltrate 

 down to the marls, and give rise to many springs always 

 situated at the foot of the rocky escarpments. 



This is the cause that there exists neither fountains nor 

 rivulets, throughout the extent of the platform, which com- 

 pels the inhabitants of the villages to consume only cistern 

 water. 



It follows also that the ground is lighter and more fit for 

 the culture of corn. 



Lastly, the waters, penetrating into the caverns, gradually 

 wear away their sides, and in the end produce sinkings re- 

 sembling those I have described in the gryphite limestone 

 formation. 



The first stage of the oolite formation is not complete in 

 the vicinity of Lons le Saunier ; the platform rises at the 

 commencement of the valley as high as the beds containing 

 entrochi and terebratulas above Conliege, to the thin and 

 regular compact limestone beds that precede it ; it is still 

 lower above Perigny. 



