Chapter II: Section X: Middle Eocene

A.—_Wadi Rayan Series._—Work of Schweinfurth and Mayer-Eymar.
Section at entrance to Wadi Muêla on Nile Valley side. Strata
of cliffs near Der el Galamûn. Detailed section measured at
Jebel Rayan. Mayer Eymar’s section in Wadi Muêla 35

B.—_Ravine Beds._—In ravines of El Bats and El Wadi. Relation
to underlying series seen at Gar el Gehannem. Section at Gar
el Gehannem. Fauna of strata. In ravines unconformably
overlain by Pleistocene, etc. Form plain bordering cultivation
on east side. Extension into Nile Valley. Occurrence at Sersena
and Tamia. Forming base of Geziret el Qorn and lower part of
northern escarpment of Birket el Qurûn. West end of lake. Hard
siliceous bands give rise to horns or promontories of lake.
Ravine Beds in the Medinet el Fayûm boring. Thickness 37

C.—_Birket el Qurun Series._—Homotaxial with quarried
limestones of Cairo. Foraminiferal beds. Extension of series.
Section at Ezba Qalamsha. Section north of Lahûn pyramid. East
of Sersena and north-east of Rubiyat. Section 17 kilometres
28° N. of E. of Tamia. Series characterized by large globular
concretions. Development and fauna in Geziret el Qorn.
Zeuglodon remains. Profile at Geziret el Qorn. Rich molluscan
fauna. Section on mainland opposite Geziret el Qorn. Section at
west end of Birket el Qurûn. Formation of earth-pillars.
Extension west of the lake. Development of the series in the
Zeuglodon Valley. Abundance of skeletons of whales. Molluscan
fauna. Pseudomorphs in celestine. Hill mass south of the
Zeuglodon Valley. Junction of Birket el Qurûn series with
overlying stage 41

D.—_Qasr el Sagha Series._—Equivalent of the Upper Mokattam
of Cairo. Greater development in Fayûm. Vertebrate fauna of
series. Schweinfurth’s original discovery of cetacean remains.
Recent discovery of land and marine mammals. Extension of
series generally. N.N.E. of Tamia. At Garat el Faras. In the
cliffs north of the Birket el Qurûn. Detailed section near
ruin of Qasr el Sagha. At Gar el Gehannem and westwards. Land
animals floated out from land by river currents. The series a
littoral deposit. Lignitic beds and thin seams of coal 49