598 MISS M. M. OGILVIE [mrS. GORDON] ON" THE [Aug. iSqQj 



character wherever they have been exposed to weather-action. 

 Brownish fossiliferous sandstones at the base ; rose-tinted or chalky- 

 looking dolomitic flagstones, sometimes with beds of dolomite: 

 brilliant red, violet, and greenish marls, and an interbedded fine, 

 variegated, or pale breccia always form the series of Eaibl strata as 

 observed by me at Sella, Sett Sass, Sass Souge, and other localities. 

 The few fossils found in this series on the Sella Mountain were 

 typical Eaibl species, and they were found in the brownish sand- 

 stones. Ostrea montis-caprilis and Gervillia Bouei were the most 

 characteristic types in these. 



The Schlern-Dolomite rock proved often highly calcareous, 

 and it was found to be comparatively easy to identify it on the 

 east side, in spite of the disturbed stratigraphical relations, after 

 the minute examination previously made on the west side up Val 

 la Stries. It contains (7z^ar?s-spines and highly-altered crystalline 

 outlines of molluscan shells in great numbers ; encrinite-remains 

 and algal structures at all horizons; occasional banks of coral- 

 growth ; and sometimes good specimens of sponges. In the highest 

 horizons the rock showed drusy cavities, with large gasteropoda in 

 them resembling the Chemnitzia found in the Wetterstein lime- 

 stone, although unfortunately I did not succeed in getting them 

 out of the cliffs. Only fragments of these and of the bivalve-shells 

 could be secured. 



The Schlern Dolomite of the Sella Mountain is emphatically more 

 calcareous and more fossiliferous than the Eaibl Series. The 

 latter is clearly a deposit which was originally magnesian. The 

 fossiliferous sandstones at the base may be said to mark the gradual 

 transition from the generally deeper-sea conditions of the previous 

 period to the shallowing and variable conditions of Eaibl time.^ 



Pian de Sas s. — The name of ' Pian de Sass,' sometimes written 

 ' Plan de Sass,' is given by the country-people to a shelving terrace 

 on the east side of Sella. As often happens, the application of the 

 name in the Government Survey map differs from the common usage 

 in the district. That map (scale ^s^joq) places the name opposite a 

 rounded summit at the southern end of the terrace overlooking 

 the Campolungo Pass. But the smaller Survey map, on the scale of 

 -TT-^QQi places the name on another outstanding rock close to a ridge 

 at the northern end of the terrace, where there is a col between 

 Corvara and the Campolungo Pass. 



I understand that this northern rock was the one visited by 

 Prof. Eothpletz, and described by him ^ under the name of Pian de 



^ ' Coral in the Dolomites,' Geol. Mag. 1894, p. 49 & pi. ii. ^^f 



^ ' G-eol. Querschn. durch die Ost-Alpen,' 1894, p. 56. I may be allowed 

 to remark that my own early observations on Pian de Sass were made in 

 1892-93 without any knowledge of those made by Prof. Eothpletz. In gthe 

 course of subsequent conversation with him, I was pleased to find that our 

 observations agreed in two important respects — (1) the identity of the Pian 

 de Sass rock as Schlern Dolomite, and not Dachstein Dolomite, as mapped by 

 lilojsisovics ; (2) the existence of a transverse fault on the east side of Sella with 

 downthrow to the west. 



