EMMRICH SOUTHERN TYROL. 23 



rolled fragments either of Nullipores or of inorganic concretions, of 

 hard limestone with Foraminifers, and of shells and other organic 

 remains. The dark-coloured pebbles are more or less excavated ; 

 sometimes the interior has all gone, leaving only a thin husk. Some 

 of the pebbles have quite disappeared, the space they once occupied 

 being only left. In consequence of the schistose structure of their 

 original rock, some of the pebbles present exfohations. Sometimes 

 their interior is occupied by an inconsistent light-grey nucleus, or 

 with incoherent dust. 



Ch. von liauer, having submitted these pebbles to chemical ana- 

 lysis, found that the yellowish-white calcareous cement was nearly 

 pure carbonate of lime, with only -^-^q of carbonate of magnesia, 

 im of insoluble residuum, and a trace of iron. A massive dark 

 grey pebble gave carbonate of lime, 98*33, and carbonate of magnesia, 

 12-000 (both carbonates nearly in the mutual proportion of 6 to 1). 

 This proportion is as 3 to 2 (carbonate of lime, 62"52 ; carbonate of 

 magnesia, 36*75) in the dust contained in the cavities. This pow- 

 dery substance, which is slowly soluble in, and feebly effervescent 

 with hydrochloric acid, ma}^ be therefore considered as being of a 

 dolomitic nature, and may be supposed to have remained after a 

 part of the carbonate of lime had been dissolved by water saturated 

 with carbonic acid, and again precipitated in a crystalline shape 

 amid the surrounding cement. 



[Count M.] 



On the Geology of the Eastern Environs of Trente, in the 

 Southern Tyrol. By Prof. Emmrich. 



[Proceedings Imp. Geol. Instit. Vienna, November 11, 1856.] 



The dolomite of Monte Calva and Monte Calls rests, in the Fer- 

 sina Valley, on argillaceous slate and red Triassic sandstone, overlaid 

 on the right side of the valley by thick bands of rolled pebbles, im- 

 bedding a stratum which contains impressions of dicotyledonous 

 leaves. These dolomites are again overlaid by still thicker masses 

 of light-coloured limestone, generally of a fine-grained oolitic struc- 

 ture, and alternating upwards with compact grey limestones ; and 

 downwards, with yellow and red limestones. Whole beds of these 

 compact limestones are full of the ''Dachstein-bivalve" [Megalodon 

 scutatus, Schafh.], associated in one locality (between Civezzans and 

 Cognola) with ChemnitzicBy 6 inches long, and large Terebratulce, 

 resembling T. Grestenensis, Suess, or T, pyriformis, Suess, in the 

 wide rostral aperture. The same strata comprise marly beds full of 

 small testacea, such as Ostrcea, Gervillia, MytiluSy &c. 



Prof. Emmrich infers from these facts, that the oolitic limestone, 

 so much developed in the Alps of South Tyrol, is an equivalent 

 of the Dachstein and Gervillia (or Kossen) strata of the Northern 

 Alps. The oolitic limestones are succeeded by red Jurassic, then red 

 and white Diphya-limestones, containing teeth of SphcEroduSy shells 

 of Terebratula diphya, Aptychi, and remains of Ananchytes. 



