NOTES ON THE EAST AFRICAN MIOCENE PRIMATES

The material to be described in this paper was obtained from Rusinga Island and Songhor, Kenya, during various scientific expeditions, primarily by members of Dr. L. S. B. Leakey's third and fourth E.A. Archaeological Expeditions, of 1932 and 1935 respectively. Additional material was obtained from Songhor by the author in 1938, and by Dr. Leakey in 1940 and 1942. Papers dealing with the whole of the collections of mammalian fossils obtained by the earlier expeditions, were prepared for publication some years ago, but unfortunately many unforeseen circumstances have combined to delay publication. The major paper, dealing with the Proboscidea, (MacInnes, 1942), which was submitted for publication in 1937, only appeared in .July, 1942, and it has now been decided that detailed descriptions of the remainder of the material should be placed on record with.out further delay. Owing to the lack of sufficient comparative material, and of much of the relevant literature, these papers must be confined largely to descriptive work,' rather than comprehensive systematic discussion. The present paper deals first-under the heading "Correlation"-with the evidence supplied by the fossil fauna of the area as a whole, in an attempt to determine the geological horizon to which the material subsequently described should be assigned. The remainder of the paper deals with the fossil Primates obtained during the expeditions referred to above. The study of some of the specimens recovered by the earlier expeditions was greatly facilitated by members of the Department of Anatomy at Cambridge University, and I should like particularly to express my thanks to Professor Harris and to Dr. Duckworth, who provided me with comparative material in this connection, and whose help and advice was much appreciated. My thanks are also due to Dr. A. T. Hopwood of the British Museum of Natural History, who enabled me to examine the types of certain fossil specimens, and to Mr. Sam Evans of Songhor, from whose farm much of this interesting material was obtained. Dr. Leakey's most recent visit to Rusinga Island, in August, 1942, yielded additional anthropoid material, including a nearly complete mandible, and a left astragalus, which are assigned to Proconsul africanus Hopwood. I am indebted to Major Hopkirk of the S.R.M.C. for his help in attempting to obtain, by X-ray, the root-cavity formation of this mandible, and certain internal features of the structure of the astragalus. It had been hoped that examination of the trabeculae of the latter might give some indication of the main line of stress, and thus suggest the normal