150 M. Chaubaut on the 



A zoophite, which I refer to the genera astrea or tubipora, 

 ■with regular hexagonal tubes, is frequently met with in the 

 compact limestone of an undetermined fracture ; some 

 pectens and terebratulae are also seen in it. 



The last beds of brittle limestone do not appear to contain 

 any species of organic remains.* 



On the last of these beds rest the marls of the next stage ; 

 but I do not propose to describe them here, because they do 

 not occur, as I have already stated, in the environs of Lons 

 le Saunier. 



Geographical Distribution of the Rocks of the Oolite 

 Formation. 



The rocks whose composition has just been described, 

 form the first step of the immense amphitheatre presented 

 by the Jura chain on the side of France ; the road from 

 Lyons to Strasbourg, for a length of four myriameters [about 

 30 miles] on each side of the town of Lons le Saunier, is traced 

 precisely at its foot in a direction from S.S.W. to N.N.E. 



To the south of the town, the edge of this step is deeply 

 furrowed and divided into longitudinal hills covered to their 

 summits with wood. On the north it presents a vast plat- 

 form cut by some transverse valleys, and bordered by well 

 cultivated knolls and hills ; these hills, of small elevation, 

 and situated on the prolongation of the slopes, are almost 

 always crowned by a few beds of yellowish rock of little 

 extent. 



Observing the sides of the valleys with care, I recognised 

 throughout their whole extent the succession of beds I have 

 noticed. 



The marls are nearly every where masked by the vege- 

 table soil J they are only seen in some broken places, so that 



* The beds described by the author between the inferior oolite and 

 the first stage, are most probably analogous to the great oolite, &c. of 

 the English series. (Trans.) 



