The sub-fossil fauna of the Fayûm alluvium, in addition to those forms everywhere met with in the Nile Valley, includes _Neritina nilotica_ and _Melania tuberculata_, which are common forms of the _Melanopsis_ stage, as well as _Unio abyssinicus_ and _Valvata nilotica_. In common with the present fauna of the Birket el Qurûn it has the five forms belonging to the genera _Corbicula_, _Neritina_, _Valvata_, _Melania_, and _Planorbis_. The sub-fossil fauna, which passes into the modern fauna of the Birket el Qurûn, shows connection with the Mediterranean and Blue Nile, but has a total absence of White Nile forms such as _Ampullaria_, _Lanistes_, _Cleopatra bulimoides_, _Spatha_ and _Aetheria_. Moreover _Limnæa palustris_, although identical with the form found on other Mediterranean coasts, is as yet entirely unknown from the Nile Valley. Blanckenhorn concludes that the diluvial subfossil deposits of the Fayûm were produced when the climate of Egypt was damper and more Europæan, the Nile carrying more arenaceous sediment in place of the mud of to-day and running at higher level, as it did when the shells of _Unio Schweinfurthi_ were enclosed in the deposits of Jebel Silsila. Blanckenhorn thinks the Nile obtained access to the depression during the last European ice period. This last supposition, coupled with the above comparison of the Fayûm fresh-water fauna with the Melanopsis stage of the Nile Valley Pleistocene series, shows that in regarding the early Fayûm lake as dating from prehistoric times Blanckenhorn and the writer are in agreement. SECTION XIV.—RECENT. We may divide the Recent period into two epochs, Prehistoric and Historic, always remembering that the line of demarcation is not much more distinct than that between Recent and Pleistocene. _O._—=Prehistoric.= The abundance of worked flints on the desert just within and around the site occupied by the Fayûm lake in late Pleistocene and prehistoric times, shows that the shores were eventually inhabited by people who made and used these primitive tools. That the edge of the lake was abundantly wooded is shown by the thousands of well preserved tamarisk stumps met with at the present day in situ (Plate XIV) in the clays throughout the former margin of the lake.