Vol. 50.] GOSAU BEDS OF THE GOSAU DISTRICT. 141 



Out of the 140 or more species of corals, most of which are 

 peculiar to the Gosau Beds, 20 are found in the Provencien. 

 Thus, taking the corals, bivalves, and gasteropoda together, we find 

 56 species in the Provencien, and this is a far larger number of 

 -species than is found in any other sub-stage, according to Zittel. 

 He finally concludes that the Gosau Beds are Turonian, that they 

 belong only to the zone of Hippurites cornu-vaccinum (Provencien), 

 and that they represent a unique and remarkable development of 

 that horizon, indicated by the richness of their fauna and its 

 large number of peculiar forms. 



There seems no doubt whatever that the Provencien zone of 

 Hippurites cornu-vaccinum occurs in the lower part of the Gosau 

 series ; but it does not follow that the Gosau Beds merely represent 

 a remarkable development of this one horizon only. It is, indeed, 

 by no means easy to correlate these beds exactly, seeing that we 

 have no stratigraphical data and considering their peculiar fauna, 

 with any well-known zone or zones of Western Europe : nor does 

 there seem to be an entire agreement amongst geological writers 

 as to exactly what should constitute the Turonian and what the 

 Senonian system. Possibly some confusion might be avoided if 

 these terms were altogether ignored in a discussion of this sort, 

 and reference only made to zones, which are probably, under the 

 present methods of stratigraphical enquiry, a surer indication of 

 a geological horizon than names for systems and stages which can 

 only have a more or less local significance. 



Zittel occupies the last part of his monograph with a sketch of 

 the principal features of the strata included in the sub-stage Pro- 

 vencien of the South of France, and with a few remarks on the 

 wide distribution in Southern Europe and Asia of the zone of 

 Hippurites cornu-vaccinum. The term ' Provencien,' however, does 

 not seem to have come into general use, many geologists including 

 the zone of Hipp, cornu-vaccinum in the sub-stage Angoumien ; 

 but this is not of any particular importance. A mere question of 

 terms cannot alter a geological horizon. 



As an example of the confusion which may arise from the use of 

 the terms ' Turonian ' and ' Senonian ' in connexion with such 

 stratigraphically isolated deposits as the Gosau Beds, I will quote 

 two passages, both from the pens of eminent geologists. In 

 1881 appeared Prof. H. G. Seeley's description of the Reptile Fauna 

 of the Estuarine Series of JSTeue Welt, 1 appended to which was a note 

 by Prof. Suess. In this, however, Suess omits to mention the occur- 

 rence of Hippurite-limestone below this series in the Gosau Beds, 

 and finally remarks, " I cannot, therefore, say positively that the 

 age of the Pep tiles .... is exactly that of your Cambridge Phos- 

 phate-beds ; but it is certain that they are older than the true 

 Turonian deposits, and especially older than the zone of Hippurites 

 cornu-vaccinum^ Turning now to Toucas's paper, 2 entitled ' Syn- 

 chronisme des Etages Turonien, Senonien et Danien dans 'e Nord 



1 Quart. Journ. Geol. Soo. toI. xxxvii. p. 620. 



2 Bull. Soc. Geol. France, ser. 3, vol. x. pp. 200-202. 



