OF THE SWISS JURA AND ENGLAND. 



241 



Exogyra virgula. Further south, at Tramelan, a small exposure 

 was observed in these beds, which consisted of yellowish marls and 

 impure limestones largely made up of the shells of Exogyra virgula. 



The Portlandian beds, which are so well developed in our 

 southern district, are almost wanting in the northern part of the 

 Jura. The only locality where they were seen in the latter district 

 is north of the railway-station at Moutier. The same remarks apply 

 equally well to the Purbeckian, as apparently they have not been 

 found further north than Moutier ; and there, overlying the Port- 

 landian, is a dark-coloured limestone, about one foot thick, containing 

 numerous freshwater fossils. In the absence of fossils it is hard to 

 define the limit between the Purbeckian and Portlandian in this 

 section (see fig. 2). 



Fig. 2. — Section in Railway -cutting north of Moutier Station. 



a, Portlandian ; b, Purbeckian. 

 The bed marked X contains freshwater fossils (Purbeckian). 



The following fossils were obtained from the black limestone 

 referred to above : — 



Chara Jaccardi, Heer. Planorbis Ckoffati, Mailt. 



Cypris valdensis, Sow. (?). Oorbula Forbesi, Be Lor. 



Bithynia, sp. Hydrobia Choparti, Sandh. 



2. The Southern" District. 



Nearly the whole of this district is described in Prof. Jaccard's 

 Memoir on the Cantons Xeuchatel and Vaud, and the following 

 classification is taken from his ' coupe theorique,' pi. 4, at the end 

 of the work referred to : — 



Groupe J urassique Superieur, 

 or Kimineridien 



Groupe Jurassique Moyen, or 

 Oxfordien 



4. Purbeckien. 



3. Portlandien or Nerineen. 



2. Pterocerien. 

 _1. Astartien. 



'4. Corallien. 



3. Pboladoinien 



2. Spongitien 



_1. Callovien. 



Oxfordien Calcaire. 



