Fluvio-marine Scries of the Fayum.* As a rule the remains are found 

 in the large lenticular deposits of river-sand which occur intercalated 

 here and there among the ordinary beds of the series. Enormous 

 quantities of fossil trees are associated with the remains, the carcases of 

 the animals evidently having been floated out to sea at the same time 

 and by the same river currents. The bones occur in a very perfect 

 state of preservation, but usually do not bear handling or removal until 

 strengthened and hardened by plaster and glue. 



The Fluvio-marine Series is of Upper Eocene to Lower Oligoccne 

 age, and in the central part of the Fayum conformably overlies the 

 < £asr el Sagha Series (Upper Mokattam, Middle Eocene). 



The forms described in the present note were all obtained from the 

 same horizon, near the base of the series, and may therefore be regarded 

 as of Upper Eocene (Bartonian) age. Of the mammals described, 

 only one genus, Ancodus (species not determined) has as yet been 

 obtained from still younger beds, Molluscan remains are wanting in 

 the lower beds, but nearer the top of the scries freshwater forms, such 

 as Unto, Lanistes, are not uncommon, while local marine bands yield 

 such forms as Turritella pharao m'caand Pleurotoma ingens, identical 

 with those of the Qasr el Sagha series (Middle Eocene) below. From 

 the occurrence of these one might infer that the series was of Middle, 

 rather than Upper Eocene age, but there is such an abrupt lithologieal 

 change at the summit of the Qasr el Sagha series, indicating completely 

 altered conditions in the area, that it is preferable to regard the 

 Fluvio-marine saries as a separate formation. Moreover, the state of 

 development of the mammalian fauna is far higher than that of the 

 Qasr el Sagha series, being almost Oligocene in character, judging from 

 comparisons with known areas. The presence, however, of distinct 

 Eocene molluscs, together with the absence of undoubted Oligocene 

 forms, in the lower part of the Fluvio-marine series, incline us to 

 regard the beds in question, containing the mammals described in the 

 present note, together with Arsinoitherium Zitteli, as of Upper Eocene 

 (Bartonian) age. 



The following table will show the divisions of the Eocene in the 

 Fayum, together with (lie horizons to which the different vertebrates, 

 so far obtained, belong: — 



(*) For fuller details of these beds see The Fayum Drjiresxion: A Preliminary Notice of flic 

 Geology of a District m Egypt containing n new Paleeogene Vertebrate Fauna, by Hugh. J. L. 

 IVadndl. Geolog. Mag. Dec IV., Vol. V1U, No. 150, pp. 510-54G, Dec. 1.001. 



