THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE IV. VOL. VII. 



No. VIII.— AUGUST, 1900. 



I. — On the Fauna of the Upper Cassian Zone in Falzarego 

 Valley, South Tyrol. 



By M. M. Ogilvie Gordon, D.Sc. 



HAVING the opportunity of revisiting Munich, I have drawn 

 up a list of the fossils which formed the basis of the " Upper 

 Cassian Zone," erected by me in 1893. These fossils,^ when 

 I discovered them in Falzarego Valley in 1891, were then for the 

 most part unknown. The tuffs and breccias in which they occur 

 had been referred by Loretz to the fossiliferous Kaibl horizon of 

 the Schlern Plateau, and by Mojsisovics to the much lower horizon 

 of Wengen strata. I found, by careful collection from strata in 

 position, that the fauna, in addition to a fair proportion of St. Cassian 

 types and a few Raibl types, comprised a number of types common 

 both to Cassian and Eaibl horizons and a still greater number of 

 species which had not been found elsewhere (Q.J.G.S., 1893, pp. 31, 

 44, 46, 47). 



Judging both from the transitional Cassian-Eaibl character of the 

 fauna and from the stratigraphical position of the fossiliferous series 

 in the field, above a zone containing typical St. Cassian fauna, 

 I concluded that this Falzarego Valley fauna represented a pala^onto- 

 logical zone younger than the typical St. Cassian fauna as known at 

 Stuores and Prelongei, and older than the lower Eaibl fauna as 

 known at Schlern Plateau and described by von Wohrmann and 

 Koken.- I therefore placed it as an independent palceontological 

 zone, naming it Upper Cassian.^ This determination of an Upper 

 Cassian zone in South Tyrol practically demonstrated the same 

 gradual faunistic transition from Cassian to Eaibl zones in South 

 Tyrol which had been demonstrated by von Wohrmann ^ in the 

 Cardita and Eaibl strata of North Tyrol. 



' My zonal collections from the Ennebcrg auci Arapezzo Upper Trias are in the 

 Palfcontological Museum in Muuicli. 



2 von Wohrmann und Koken : " Die Faunen der Raibler Schichten von Schlern- 

 plateau" : Zeitsehr. d. D. geol. Ges., 1892. 



^ Ogilvie: "On the Wongen and Cassian Strata in Southern Tyrol," Quart. 

 Journ. Geol. Soc, 1893 ; " Coral in the Dolomites," Geol. Mag., 1894. 



* von AViJhrmann: " Die Fauna der sogeuannten Cardita u. Raibler Schichten 

 in den Xordtiroler u. bayerischen Alpen" : Jahrb. der k.k. geol. lleichs., 1883. 



DECADE IV. — VOL. VII. — XO. VIII. 22 



