w. 



182 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 13, 



de Jaman *, so well known to tourists, where masses of the mottled 

 limestone with flint nodules repose on dark schists and impure hme- 

 stones as thus represented. From that peak there is apparently a 



Fig. 4. 



Vevey. 



IMolasse. Fault. Lower Jura. Strike N. & S. Oxfordian. 



descending succession through other limestones, as exposed in the gorge 

 of the Baye de Montreux near Glion, down to the black fetid limestones 

 and shale at the bridge of Montreux, which may represent the liasf . 

 Again, when wandering through the Swiss Alps, whether on the 

 lakes of Thun and Brientz, on the upper portion of the Lake of the 

 Four Cantons (fig. 12), or on the northern shore of the lake of Wallen- 

 stadt (fig. 14), I came upon calcareous bands, which Studer, Escher, 

 and the best Swiss geologists consider to be of Oxfordian age, some- 

 times surmounted by limestones the equivalent of the coral rag, and 

 sometimes ivithout them, but invariably covered by the neocomian 

 limestone, as in the Savoy section (fig. 3). The Portland limestone, 

 so copiously developed in the Jura, and so rich in fossils at Soleure, 

 has not as yet, to my knowledge, been found in the Alps J. It is only 

 indeed by fossils (and unfortunately they are of rare occurrence in the 

 alpine limestones) that the strata can be actually referred to the respec- 

 tive members of the Jurassic or oolitic series. Resting upon carbona- 

 ceous schists, which in their turn overlie the so-called " Sernft con- 

 glomerate " and quartzose talc slate, the upper part of the lower divi- 

 sion of the Jurassic rocks of the canton Glarus, in parts dolomitic 

 (" Zwischen-bildungen " of Studer), are characterized in their upper 

 member by the diffusion of iron ore in an oolitic matrix. It is this 

 rock which contains the Ammonites Gowerianus (Sow.), A. macro- 

 cephalus (Schloth.), A. Parkinsonii (? ?), Ostrea pectiniformis 

 (Schloth.), O. calceola (Goldf.), and Terehratula digona (Sow.), &c. 

 The overlying stage, or that which immediately succeeds to the 

 ferruginous oolite (the " Hoch-Gebirg's Kalk" of the late M. Escher), 

 as seen in the cantons of Glarus and Appenzell, contains the charac- 

 teristic forms Afnmonites biplex and A. polyplocus, with belemnites, 

 and is therefore a good representative of the Oxfordian of the Alps§. 



* 1872 metres above the sea. 



t M. Collon informed me that the Ammonites Petit Thouars (d'Orb.), a lias 

 fossil, had been found in the black limestones and schists which are exposed iu 

 the gorge above the little bridge, dipping under the mass of the adjacent moun- 

 tains. 



X The abundance of tortoises and other peculiar fossils which characterize the 

 " Portlandian " of Soleure, indicate the local character of the formation, and the 

 same may, indeed, even be said of the Portland rock of England. 



§ For the description of the lithological varieties of these Alpine Jurassic rocks, 

 see the Gebirgskunde of M. Arnold v. Escher, included in the general natural- 

 history account of the Canton Glarus by Professor Heer of Zurich. 



