INTRODUCTION. 
xii 
(i l(ia)ifoj)his, &c., were collected from the Middle Eocene beds, and it was arranged 
to revisit the district for the purpose of obtaining further material. This was done, 
and result('d not only in the collection of much that was new from the Middle Eocene 
escarpinent, hut also in the discovery that the Eluvio-marine beds above were bone- 
Ix'aring and in the finding of the first traces of Palwomastodon. Towards the end of 
the same year Mr. Beadnell returned to the district and paid special attention to the 
Eluvio-marine beds, from which he obtained the first remains of Arsinoitherium, as 
well as of other now mammals and reptiles ; he was also fortunate in finding a spot 
where bones occur in considerable numbers in a limited area, instead of being widely 
scattered as is usually the case in these deposits. His expeditions in the winters 
of 1902-3, 1903-4, resulted in the accumulation of a very lai’ge mass of material 
(only part of which is here catalogued) in the Geological Museum at Cairo. During 
the springs of 1902 and 1903 the present writer also collected in the same district, and 
obtained a considerable number of specimens, including several new forms. Lately 
Baron E. Nopesa visited the Fayiim and made a collection of vertebrate remains, 
including some good specimens which he presented to the British Museum : these 
are referred to in the present Catalogue. In the early part of 1902, Drs. Stromer 
and Blanckenhorn also made a short stay in the district, and their collections of 
vertebrate fossils have been in part described: the Zeuglodonts (38, 40, 41) and 
fish-remains (43,44) by Dr. Stromer himself ; the Chelonians by Dr. Reinach (34); 
while Dr. O. Abel is preparing a memoir on the Sirenia, including also the earlier 
forms from the Mokattam Hills (see also i). 
The collections of remains noiv preserved in the British Museum and in the 
Geological iSIuseum at Cairo comprise representatives of all the main divisions of 
the vertebrate pbjlum except the x^mphibia. Both in point of numbers and interest, 
the Mammals are by far the most important ; next to these come the Reptiles, while the 
Birds are represented by mere fragments of a single species. 
The Mammals may be divided into three sections : — (1) the land-mammals which 
seem to be truly endemic to the Ethio])ian region ; these occur both in the Upper and 
Middle Eocene beds, and include such genera as Mceritheritim, PaJwomastodon, 
Arsiuoithcrium, Paiy/flterium, j\fe(jalolnjrax, Sayhatherhon, and perhaps Geniohijus-. 
(2) forms of which close allies occur in other regions in approximately contemporary 
deposits ; these, so far as at present known, occur only in the Ujiper Eocene beds, 
and include such genera as Aiicodon, Khagatlicrinin, Ibjmnodon^ Pterodon^ Apterodon, 
and Sinopa \ (3) the aquatic mammals so far not found in the U])per Eocene beds. 
