Miss M. M. Ogilvie — Coral in the "Dolomites" 51 



white, above the Schlern dolomite. From the occurrence of similar 

 beds on the Sella massif, I took them to be of Kaibl age, but 

 followed along their dip to the north-east and saw their gradual 

 passage into ordinary-looking yellow sandstones, with numerous 

 fossils which proved to be the typical Raibl fauna of Travenanzes 

 Valley. As the Travenanzes horizon is palaeontologically younger 

 than that of the Schlern plateau deposits, some part of the dolomite 

 of Lagazuoi must in reality be of the same age as the fossiliferous 

 Eaibl beds of Schlern age. Thin beds of Cipit Limestones, like 

 those of Cassian age, but much harder and whiter, occur at Valparola 

 and Falzarego interbedded with the Travenanzes fossiliferous horizon. 

 Enough has been said to show that some of the anomalies of 

 " Schlern dolomite " fall in the Eaibl period, which has not been 

 included by Mojsisovics in the Coral Reef epoch. Yet the heteropism 

 of the Eaibl strata adds to, and takes away from, the apparent 

 thickness of the dolomite " reefs." It will be remembered that a 

 younger or Upper horizon of fossiliferous Cassian strata is present 

 in Ampezzo, which is absent in the Fassa and Groden districts, and 

 we know now that the upper part of the Schlern dolomite rock is 

 contemporaneous with fossiliferous Eaibl beds. Going a step farther, 

 we can see that by thinning off the dolomite both at its upper and 

 lower horizons, it would be probable enough, especially in the 

 Ampezzo area, that fossiliferous Eaibl strata should rest on fossil- 

 iferous Cassian strata. According to Mojsisovics, this is actually the 

 case. My reasons for not adopting this view have been already stated 

 (Quart. Journ. Geol. Soc. 1893, pp. 64-69). It is true that in these 

 valleys the Schlern dolomite becomes comparatively thin, and it 

 looks like the dolomite rock interbedded at higher horizons of 

 Eaibl strata. But even if the dolomite rock were wholly or in 

 part contemporaneous with fossiliferous Eaibl strata elsewhere {e.g. 

 the Schlern plateau strata), this would in nowise afford evidence in 

 favour of the Coral Eeef theory, but only of the familiar fact of 

 Eaibl heteropism. The important feature is that the dolomite bears 

 no evidence of Coral building, and is no thinning-out prolongation 

 of a "reef"; but is here and elsewhere in the Cortina valleys an 

 independent horizon of dolomite above the Cassian fossiliferous 

 beds — it is, therefore, not Cassian "reef-dolomite." The varying 

 relations of Cassian, Schlern dolomite, and Eaibl strata are repre- 

 sented in Diagram IV. 



The Eaibl deposits pass quite gradually into the overlying true 

 marine deposit, Dachstein dolomite, with which an important faunal 

 link connects it. Several species of the bivalve Megalodon appear 

 in the highest Eaibl strata, and this is the predominating genus 

 in Dachstein dolomite. There are dolomite shales of Dachstein age 

 undistinguishable from those of Eaibl age, and dolomitic marls 

 make their appearance now and then in true Dachstein horizons. 

 The two rocks, Schlern dolomite and Dachstein dolomite, are so 

 much alike that one experiences in the field the utmost difficulty 

 in distinguishing them. The characteristic Dachstein bivalves so 

 common in some parts of the rock are entirely absent in others. 



