﻿122 PJiOE. E. W. SKEATS ON THE [Feb. I905, 



Monte Cristallo. 



No. 46. South side of Monte Cristallo, immediately below the 

 Baibl Beds. 



The crystals of dolomite have dark centres. No organisms are 

 recognizable ; but darker areas possibly represent shell-sections. 



Tre Croci. 



No. 40. Prom an exposure of dolomite, east of Tre Croci. 

 Sections of ill-preserved organisms may represent calcareous 

 algse. The matrix of the rock is cloudy and granular. 



No. 41. Prom 50 feet below No. 40. 



A coarsely-crystalline, rather cloudy dolomite, containing no 

 traces of organisms. 



The Diirrenstein Area. 



No. 66. Prom the summit of the Diirrenstein (9300 feet). 

 An almost clear, cavernous, coarsely-crystalline dolomite, devoid 

 of organisms. 



No. 68. About 500 feet above the Diirrenstein Hotel. 

 A fine-grained, rather cloudy dolomite, in which darker, more or 

 less circular areas may represent the remains of calcareous algae. 



The Drei Zinnen Area. 



No. 71 a. Block in a stream at the head of the Bienz Valley. 



Broad areas of clear, coarsely-crystalline dolomite occur, with dark 

 areas of smaller cloudy crystals arranged in a more or less meandrine 

 way, and suggesting the former presence of corals. 



No. 70. Prom the head of the Bienz Valley, the northern base 

 of the Drei Zinnen. 



Much of the section consists of cloudy dolomite. Cavities are 

 lined or filled with more coarsely-crystalline, clearer dolomite. 



Sections from calcareous rocks both above and below the horizon 

 of the Schlern Dolomite were made, and descriptions of some of the 

 more important rocks are here appended. 



Below the Schlern Dolomite. 



Wengen Limestone. 

 Seiser Alp. 



No. 22. Prom the ravine just below the Selaus Alp Hut, Frombach. 



A rock consisting mainly of small patches of granular calcite, 

 fragments of shells, and of very-finely divided volcanic fragments, 

 grey-brown in colour, and polarizing as an aggregate. Some 

 elongated opaque particles scattered through the section are seen, 

 on examination by reflected light, to consist of pyrite. 



