OF THE SWISS JURA AND ENGLAND. 



235 



Pholadomya coneinna, Ag. 



lasviuscula, Ag 



Lima pectiniformis, Schl... 



Locality. 



Plicatula serniarniata, Et )■ Liesberg. 



Modiola imbricata, Sow 



Cardiuin intextain, Milnst 



Pecten globosus, Que?ist 



inceqidcostatus, Phil 



articulatus, Schl 



St. TJrsanne Tunnel. 



Khynchonella Tburinanni, 

 lacunosa, Schl. 



Voltz 



Terebratula insignis, Schiib 



delemontana, Opp 



Waldbeiinia bucculenta, Sow 



Cidaris florigenmia, Phil 



Hemicidaris crenularis, Ag \ Liesberg. 



Pseudodiadema aroviense, Et 



G-lypticus hieroglyphicus, Ag 



Collyrites ringens, Ag 



bicordata, Des „ 



Millericrinus echinatus, Quenst 



Apocrinus polycyphus, Th. et Et 



Thecosmilia annularis, Flern Tbiergarten. 



Isastrea explanata, Gold/. Liesberg. 



Oolithe Corallienne and Calcaire a Nerinees. — Passing up from 

 the bluish limestones and clays of the ' Terrain a chailles siliceux,' we 

 come to a grey or white oolitic limestone, which usually contains 

 numerous fragments of shells and corals ; the whole is from 16 to 

 33 feet thick. This constitutes the Ooliihe Corallienne. Over- 

 lying it is the Calcaire a Nerinees, a rock somewhat variable in cha- 

 racter, but always composed of limestones, which may be compact 

 in texture, whilst at other times they are chalky, tuffaceous, and 

 quite soft ; its thickness varies from 60 to 270 feet. 



These Corallian rocks are more easily denuded than the overlying 

 Astartian ; consequently, in the escarpments, where both are seen, 

 the Corallian beds are always weathered out into hollows and 

 caverns, whilst the overlying strata project as overhanging ledges ; 

 in this way, the beds are easily recognized. 



A good section of the Corallian, Astartian, and Pterocerian is 

 seen on the roadside at Vorbourg, wear Delemont. Aided by 

 M. Mathey, we were able to work out almost every bed in the 

 above stages. The section in the Corallian here is as follows, the 



beds being given in descending order : — 



ft. 



8. Compact, fine-grained limestone 22 



7. Compact, tbick-bedded limestones, with Nerinaa . 18 

 6. Thin-bedded, coarse, subcrystalline, and pisolitic 



limestones 4 



5. Compact limestone 15 



4. Tbick-bedded, white limestone, with corals, Di- 



ceras, &c 18 



3. Irregularly bedded whitish limestone 14 



2. Thick limestones, sometimes oolitic 17 



1. Greyish oolitic limestone 32 



E 2 



