Geology and Natural History. 81 



tainly vegetable, in the sericitic (hydromica) schist of Guttanen. 

 Such facts may leave some doubts still, but they afford, at least, 

 a strong presumption that there is not the long unrepresented 

 interval between the Archaean and Carboniferous which has been 

 claimed by some ; on the contrary, that the Silurian and Devo- 

 nian may be represented in different parts of the Swiss as well as 

 in the Austrian Alps. 



Mr. Renevier continues with an account of the extensive dis- 

 tribution of the Carboniferous beds in the Swiss Alps; of the 

 Triassic, but mostly the upper Trias, and, unlike the Austrian, 

 without marine fossils; and of the Triassic and Jurassic, which 

 in the Rhetian beds — here referred to the Lias rather than the 

 Trias — include the first of the marine beds in this series. These 

 marine beds are stated to indicate, apparently, that the sea en- 

 croached on the region of the Alps in a direction to the south- 

 eastward, the Rhetian beds not extending to the High Alps, the 

 upper Lias reaching farther in that direction than the Rhetian, 

 and the Upper Jura, or Malm, constituting the calcareous back- 

 bone of the mountains, being found between the different crystal- 

 line centers of the Alps, on both flanks of Mt. Blanc, in the val- 

 ley of Chamouni on the north and that of Entreves on the south ; 

 and also at Zermatt at the foot of Mt. Rosa. The fossils in the 

 limestones of these high regions are not determinable, but the 

 beds can be followed even along the metamorphic regions, to 

 places where, as at Moeveran, the fauna is determinable. It 

 hence appears that, at this Jurassic period, the sea had its largest 

 extension, and the Alps were an archipelago, consisting of more 

 or less oblong islands. After this there is evidence of a gradual 

 retreat of the waters. 



As the geological chart shows, the Cretaceous beds occupy 

 only the outer zone of the northern Alps. The Lower Cretaceous 

 beds have the greatest extension. Passing to the later epochs of 

 the Cretaceous, the distribution shows a gradual retreat of the 

 sea. The Lower Cenomanian beds of the Upper Cretaceous are 

 the last and are only circumferential in distribution ; after this 

 the emergence of the Alps was carried on through the Cretaceous 

 until it was complete. 



The upward movement of the Cretaceous era probably con- 

 tinued through the era of the oldest Eocene (Paleocene, anterior 

 to the ISTummulitic beds), so that at this time the Swiss Alpine 

 region was continental. After this a return of the sea com- 

 menced at each extremity of the Alps, producing the Nummu- 

 tic deposits of Kressenberg, Bavaria, and of Appenzell and 

 Schwytz which is prolonged even to Lake Thun ; and also other 

 beds in the southern part of Savoy ; the intermediate region be- 

 ing still "terra firma," as proved by terrestrial and lacustrine 

 deposits. The Nummulitic beds were followed by the Flysch — 

 a marine deposit of the later Eocene ; and after it, came a new 

 retreat of the waters. 



Am. Jour. Scr.— Third Series, Vol. XXXV, No. 205.— Jan., 1888. 

 5a 



