M. Ogilvie Gordon — Fauna of Upper Caasiau, South Tyrol. 315 



to say, I never found Pachycardia Haueri, whicli is sucU a numerously 

 represented type in the Schlern Plateau strata. The limited colonial 

 aspect of local faunas seems to have been the leading palfeontological 

 feature of the Cassian-Raibl period. 



Whilst the age of the intervening calcareo-dolomitic and sandy 

 series is quite securely fixed by the presence of the Mi/ophoria and 

 Ostrcsa fossil zones above, and the Avicida Tofance and Cortinensis 

 fossil zones below, I have always referred to it in previous 

 papers as " Schlern Dolomite," following the original intention of 

 von Richthofen, who applied this term to any doloraitic facies of 

 Upper Triassic tufaceous series in the district. The fossiliferous 

 Upper Cassian tufi"s are present at Pec di Palu, south of the 

 Falzarego road, and may be followed over Valparola, Pordsi, and 

 Sella Pass to the south of Langkofl and Mahlknecht. Remnants 

 of the series occur at Cra di Mont, Crap di Sella, Freina Meadow, 

 and elsewhere farther north. 



I already showed, in 1893-4:, that throughout Enneberg and 

 .Ampezzo the horizons of Baibl time were those which displayed the 

 most extreme and complex facies relations. All Raibl zones pass 

 now at one place, now at another, into local massive developments 

 of Schlern Dolomite (e.g. Lagazuoi, Dtirrenstein, etc.). The Upper 

 Cassian zone also presents varying local facies relations within 

 Enneberg and Ampezzo, but the Wengen and Stuores-Cassian zones 

 underlie the dolomitic deposits in Enneberg and in all parts of 

 Ampezzo which I have examined. Thus, the identification of 

 successive palasontological zones proves that the tufaceous invasions 

 overspread the floor of the Enneberg and Ampezzo areas more 

 generally in the earlier periods of the Upper Trias epoch in South 

 Tyrol. And the passage-limit between the tufaceous material and 

 the ordinary sediments was at that time locally situated within 

 that wide 'Buchenstein-Mahlknecht' series of lavas and tuffs which 

 'represents one of the chief local areas of contemporaneous eruptive 

 fracture-planes. These are the heteropic conditions which I have 

 depicted in a series of diagrams, showing the successive stages in 

 the accumulation of deposits, and the intermixture from time to 

 time of volcanic material during the Wengen, Cassian, and Raibl 

 periods ("Coral in the Dolomites," 1894:, Geol. Mag., PI. II). 



In the second part of the same paper (in the Geol. Mag.), Sasso 

 Pitschi (a small mountain that occurs in the Buchenstein-Mahlknecht 

 passage-area of facies) was selected as an example of the tendency 

 displayed by later clifi"erential movements to coincide with the 

 original passage-areas between different lithological groups of strata, 

 whether these areas occurred in the horizontal extension of different 

 rock facies, as at Sasso Pitschi, or in the ordinary geological suc- 

 cession. My publication ^ in 1899 rests on the same standpoint. 



' " Torsion - Structure of the Dolomites": Quart. Journ. Geol. Soc, 1899. 

 Attention may he directed here to a printer's slip that unfortunately evaded nie in 

 the proofs, and which causes some confusion : see p. 580, imder ' 5,' near the 

 bottom of the page : "A and C to be moved counterclockwise, B and D clockwise," 

 should read " A and C to be moved clockwise, B aud D counterclockwise." 



