540 Hugh J. L. Beadnell — The Fayum Depression. 



EXPLANATION TO PLATE XVIII. 

 Devonian Fossils from Torquay. 



The specimens belong to the Torquay Natural History Society, and were obtained 

 from the foundations of its Museum. They are drawn to natural size. 

 Fig. 1 . — Capultis priseus, Goldfuss ? 



Fig. 2. — Spirifera curvata, Schlotheim, sp. Portion of ventral valve. 

 Fig. 3. — The same. Central part of the front of dorsal valve, showing the fold. 



Fig. Za, portion of surface magnified. 

 Fig. 4. — Pentamcrus galeatus, Dalman, sp. 

 Fig. 5. — The same. 



Fig. 6. — Athyris concentrica, von Buch, sp. A small dorsal valve. 

 Fig. 7. — OrtJwtetes mnbracidmn, Schlotheim, sp. Mould showing the minute 



ornamentation. Fig. 7a, portion of the mould magnified. 

 Fig. 8. — Stropheodonta taniolata, Sandberger, sp. Lower valve and hinge-line. 



Fig. 8«, portion of hinge-line magnified. Fig. 85, portion of front of 



the valve magnified, showing the double series of striae. 

 Fig. 9. — The same. Lower valve showing internal arrangements. Fig. 9a, portion 



of hinge-line magnified. Fig. 95, portion of ovarian area, showing its 



pitted surface. 

 Fig. 10. — Orthis, sp. Fig. 10«, cast of dorsal aspect. Fig. 105, cast of ventral 



aspect. 

 Fig. 11. — Cladochonus cf. Schliiteri, Holzapfel. Mould of the part of a specimen. 

 Fig. 12. — Pleurodictyum '? pachyporoides, n.sp. Portion of a ramose cast. Fig. 12a 



portion of one of the corallites magnified, showing the an-angement of 



the rods. 



II. — The Fayum Depression : A Preliminary Notice of the 

 Geology of a District in Egypt containing a new Pal^o- 

 gene Vertebrate Fauna.^ 



By Hugh J. L. Beadnell, F.G.S., F.P.G.S., of the Geological Survey of Egj'pt. 



THE Fayum, one of tlie largest depressions of the Libyan 

 Desert, is situated some 50 miles south-west of Cairo. It is 

 cut out in rocks of Eocene and Oligocene age, while still younger 

 deposits of Pliocene and Post-Pliocene date are found within the 

 hollow. The depression owes its origin to the action of the ordinary 

 subasrial denuding agents, which I have shown in previous papers 

 were capable of producing the oases-depressions of Baharia, Farafra, 

 Dakhla, etc. Faulting, which has played so important a part in the 

 formation of the Nile Valley, appears to have had little or nothing 

 to do with the production of the Fayiim and other depressions of 

 the Libyan Desert. 



During my survey of the Faytim in 1898 I found that certain 

 strata of the Middle Eocene were veritable ' bone-beds,' being 

 crowded at many points with vertebrate remains, such as the ribs 

 of cetaceans, crocodile vertebrge, fish-bones, and coprolites. Up to 

 that time the only vertebrate fossils which had been obtained from 

 the district were remains of Zeuglodon and some fragments of 

 a mandible thought to belong to Choeropotamiis ; these had been 

 collected by Schweinfurth and noticed by him in 1886, 



1 Communicated in abstract to the British Association at Glasgow, 1901, by 

 permission of Sir William Garstin, K.C.M.G., Under-Secretary of State, and 

 Capt. H. G. Lyons, Director- General of the Survey Department, Cairo. 



