236 



MR. T. ROBERTS ON THE UPPER JURASSIC ROCKS 



The ' Terrains a chailles siliceux,' which should come below, are 

 not now exposed. 



This section is also described by Greppin (op. cit. p. 87), but we 

 could not make our measurements quite agree with those published, 

 especially in the upper part of the series. 



At the roadside east of Soyhiere a quarry is opened in the upper- 

 most division of the Corallian ; the rock is a whitish limestone, part 

 of which is hard, but the greater portion is quite soft and tuffaceous, 

 and the whole rock is largely made up of corals. 



These beds are also seen at Thiergarten, Courrendlin, and again 

 near Roche, and also at Montmelon. Just behind the station, at 

 St. Ursanne, is a thick series of white limestone ; its lower part is 

 somewhat oolitic, but higher up it is quite tuffaceous and contains 

 numerous Gasteropods. A little further to the east, at the west end 

 of the bridge which spans the valley, and apparently somewhat 

 lower in the series, a similar tufTaceous limestone occurs crowded 

 with Diceras. Then, again, in the railway -cutting on the eastern 

 side of the valley, still lower beds are seen overlying the ' Terrain a 

 chailles siliceux ' as a well-bedded, coarse, oolitic limestone. We have 

 therefore here nearly a complete section in the Corallian between 

 the ' Terrain k chailles siliceux ' and the Astartian, and in it the fol- 

 lowing beds are recognized, in descending order :— 



4. Tuffaceous limestones crowded with Grasteropods. 



3. Oolitic limestones. 



2. Tuffaceous limestone with Diceras. 



1. Oolitic limestone. 



Further west, at Caquerelle, these Corallian beds occur as a white 

 oolitic limestone, which has yielded a large number of corals. 



The fossils obtained from the Oolitlie Corallienne and Galcaire 

 a Nerinees are given in the accompanying list. 



Fossils from the 'Oolithe CoraJUenne ' and 'Calcaire a Nermhs? 



Purpura Lapierrea, Buv... 

 Cerithium corallense, Buv. 



buecinodeum, Buv. .. 



cf. muricatum, Sow. 



Nerinea speciosa, Voltz . . 



nodosa, Voltz 



elegans, Thurm 



Defrancei, Desk 



bruntrutana, Thurm. 



ursicina, Thurm 



Roemeri, Philippi 



Nerita canalifera. Buv. .. 



St. Ursanne. 



Caquerelle. 











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