62 PROCKEDINGS OF THE MALACOLOGICAL SOCIKTl'. 



the Oligocene of Spain, would be in favour of a similar age for tlie 

 Palceomastodon and associated vertebrates of the Fayum. 



Such views, liowever, have been objected to by Dr. Oppenheim,' 

 wlio regarded the Pal(eomaslodo7i beds as of Ludian age and on 

 the same horizon as the ' Gypse de Paris ', in his own language 

 stating very explicitly : " Ue cette raaniere on pourrait a la rigueur 

 I'age des couches a Palmomadodon et Arsinoitherium comme Ludien." 



Dr. Oppenheim further mentioned the occuiTeiice of the mollusca 

 in the upper part of tlie series, which he unreservedly regarded as 

 of Eocene age. A reference was likewise made to Mayer-Eymar's 

 discovery of a molluscan fauna at ' Walther Hill ', one of the 

 so-called ' Sandberger Hills ', which are situated some 20 kilometres 

 west of the Great Pyramids and to the north-east of tlie Eayum 

 escarpment, and consequently outside the limits of the Fayum 

 depression, where Natica crassatina and other sliells had been found, 

 and considered to belong to the Lower Tongrian stage of the 

 Oligocene. This was followed by a second statement from Professor 

 Deperet" involving further vertebrate evidence in support of the 

 Oligocene age, he being of opinion that the Palfsomastodon of the 

 Fayum is more recent than the Palceotheriuni fauna of the ' Gypse 

 de Paris '. lleferring to the shells found high up above the verte- 

 brates, he mentioned their bad preservation, although one of tiie forms, 

 Tarritella angulata of Sowerby, related to T. Pharaonica, Cossmanu, 

 which is usually in a good condition, was quoted as ranging from 

 Middle Eocene to the Priaboniau of Eastern countries such as Tunisia, 

 Syria, and India. Professor Deperet also called attention to the 

 Oligocene facies (already acknowledged) of tlie shells determined 

 by Dr. Blanckenhorn and Mayer-Eymar. including Natica crassatina, 

 etc., which were really from the ' Sandbeiger Hills ', and therefore 

 not within the region of the Fayum. 



"With the exception of Dr. A. von Reinach, who adopts the 

 geological horizons for the vertebrate beds of the Fayum, as recognized 

 by Dr. Blanckenhorn, Mr. Beadnell, and Dr. Andrews, we find 

 that later investigators on the subject, such as Professor H. F. Osborn, 

 Dr. E. Stromer, Professor Fraas, and Dr. M. Schlosser, accept 

 Professor Deperet's views as to the Sannoisian-Stampian stage of 

 the Oligocene formation being the correct geological horizon for 

 the so-called PaJaiomastodon beds of the Fayum. Quite recently 

 Dr. Dacque, in his memoir on the fossil tortoises of Egyjit, has 

 expressed similar stratigraphical views. 



A summary of these opinions may be interesting: — 



1900. Dr. Blanckenhorn, assisted by Dr. Oppenheim, regarded 

 the mollusca of the Jebel el Qatrani deposits as of Upper Eocene or 

 Bartonian age and on the horizon of the Beauchanip Sands of the 

 Paris Basin. 



^ P. Oppenheim, "Observations sur Page des couches a Palceomastodon du 

 Fayoum " : Bull. See. geol. France, ser. iv, vol. vii, pp. 358-60, 1907. 



- Ch. Deperet, "Sur I'age des couches a Palceomastodon du Fayoum": 

 Bull. Soc. geol. France, ser. IV, vol. vii, pp. 455, 456, 1907. 



