Introduction. 9 



however, must now be withdrawn as after a further revision and study of the 

 molluscs I am convinced that the presence of the Congo Gastropod, previously 

 referred to from this Nigerian locality could no longer be supported, its 

 characters agreeing entirely with the Egyptian shell. Considering, therefore, 

 this fact and other details in connection with the fauna, its age must now be 

 attributed to the Upper Lutetian stage of the Eocene formation at the same 

 time recognising that the Bartonian facies is also very apparent. 



Before concluding these preliminary observations, it is only right to mention 

 that a good deal of this report had been prepared during my official connection 

 with the Geological Department of the British Museum, and that since my 

 retirement from public service in 1920 I have been enabled to complete it 

 through kindly facilities allowed me by Dr. A. S. Woodward, F.R.S., the 

 Keeper of the Geological Department. I wish to record my thanks to Messrs. 

 E. Heron-Allen, F.R.S., and A. Earland, F.R.M.S., for their valuable 

 " Appendix " on the Foraminifera from these deposits ; to Mr. Philip Dollman 

 for his excellent photographs of the shells which form the plates of the report ; 

 to Mr. H. B. Rowbotham, of the Geological Department of the British Museum, 

 for his ever willing assistance especially in connection with the typing of 

 my manuscript ; as also to Mr. C. D. Sherborn, who from time to time 

 has offered many useful suggestions on questions of literature. Lastly, my 

 best acknowledgments are due to Dr. J. D. Falconer, M.A., F.G.S., 

 Director of the Geological Survey of Nigeria, who has evinced the greatest 

 interest in this work and to whom I am indebted for bringing about its 

 publication. 



1 Abstracts Proc. Geol. Soc. London, 1916, No. 989, p. 51 ; ibid., 1919, No. 1042, p. 101. 



2 Abstracts Proc. Zool. Soc., London, 1916, No. 158, p. 30; Proc. Zool. Soc., London, 1916, 



pp. 519-524, text-figures ; ibid., 1920, pp. 309-319, plates i, 2. 



3 On Raetomya, a new genus of Pelecypoda, from the Tertiary Rocks of Egypt and Southern Nigeria : 



Proc. Mai. Soc., London, 1919, Vol. 13, pp. 79-84, plate i. For the favour of reproducing this 

 published plate and text in the present work, I beg to thank the Council of the Malacological 

 Society of London. 

 * Abstracts Proc. Geol. Soc., London, 1919, No. 1042, pp. 100-105 ; ibid., pp. 101, 102. 



