lt)4' M. Brongniart on the position .' 



of small size, sometimes even thin enough to serve as the " 

 covering of a house instead of slates, alternating with black- 

 ish calcareous schist, and traversed by spathose carbonate of 

 lime perpendicular to the fissures of stratification. These 

 beds, though inclined in all directions, though contorted in 

 every kind of manner, indicate a general rising towards the 

 N.E., i. e. towards the primordial mountains, found at 

 Bellano and Rezzonico. 



Here there is a rock which, according to many geologists, 

 presents very many of the characters attributed to the tran- 

 sition rocks ; and, if it is added, that near the village named 

 la Cadenabbia, I have observed in it sulphuret of zinc and 

 madrepores, as in the limestone of Namur, Bristol, &c. 

 I shall have nearly completed the characters of transition 

 limestone. 



But if, on the other hand, I add that this same rock con- 

 tains a great number of fossil shells, such as ammonites, and 

 especially turbines and bivalves resembling isocardise, all 

 shells in too bad preservation to be determinable, that nei- 

 ther entrochi, nor orthoceratites are seen in it, many geolo- 

 gists would no longer admit it among these ancient rocks, 

 which, according to them, do not contain any of the organic 

 bodies I have mentioned. 



Now, if even these rocks, which offer the characters of the 

 transition formation much more decidedly than the sandy 

 limestones of the Apennines, cannot with certainty be re- 

 ferred to it, ought not the latter to be attached to a still 

 more recent epoch ? 



I should have a much greater number of examples on the 

 northern end north-west side of the Alps. I shall content 

 myself with mentioning three : 



1. The Gemmi above the baths of Leuk, in the Valaisj 

 and that portion of the Alps that extends from this moun- 

 tain to that of Pillon, or to the commencement of the Val 

 d'Ormond, and which comprises the origin of the transverse 

 valleys of Kander, Adelboden, Anderlenk, and Gsteig. 



