ABERNETHY, James, Esq., M. Inst. C.E., F.R.S.E., M. Inst. M.E., and Formerly President of the Institute of Civil Engineering.
ALCOCK, Sir J. Rutherford, K.C.B., Hon. D.C.L. (Oxon.), Com. Ord. Isabel of Spain, Formerly President of the Royal Geographical Society.
BARTON, John Kellock, Esq., M.D. Trin. Coll. (Dubl.), Formerly President of the Royal College of Surgeons, Ireland.
BAXTER, Robert Cordy, Esq., F.R.I.B.A.
BENSON, General Robson, F.L.S.
BENT, James Theodore, Esq., M.A. Wad. Coll. (Oxford), F.S.A., Mem. Hellenic Soc., Mem. Anthrop. Inst., F.R.G.S.
BRADY, Sir Thomas Francis, R.D.S.; Inspector of Fisheries Ireland.
BRODIE, Sir Thomas Dawson, Bart., of Idvies, W.S., F.R.S.E.
BROOMHEAD-COTTON-FOX, Barnard Platts, Esq., Mem. of Counc. Inc. Law. Soc.; Fell. Roy. Hist. Soc.
CHAMBERLIN, Humphrey B., PH.D. (U.S.A.), F.R.A.S.
CHISHOLM, James, Esq., F.S.A. (Scot.).
CLARK, Robert, Esq., F.R.S.E., F.S.A. (Scot.).
CLARKE, Hyde, Esq., Vice-Pres. Roy. Hist. Soc. and Anthrop. Inst.; Mem. of Counc. S.S., Mem. Num. Soc.; For. Mem. Anthrop. Inst. (N.Y.), Corr. Mem. Royal SS. (N.S.W. and Vict.).
COPLAND-CRAWFORD, Major P. W. G., F.R.G.S.
COUPER, James, Esq., Jun., Mem. of Counc. Scot. Soc. Litt. and Art.
DE SOUZA, Sir Walter Eugene, Knt., F.R.G.S.
DE TABLEY, Lord, M.A. (Oxon.), F.S.A.; Barrister.
DRINKWATER, Harry George Walter, Esq., F.R.I.B.A.; Mem. Roy. Arch. Inst.
DURHAM, Arthur Edward, Esq., M.B. (Lond.), Formerly Vice-President and F.R.C.S. (Eng.), F.L.S., F.R.M.S., Surgeon and Lecturer in Guy's Hospital.
EWING, Lieut.-Colonel Alexander, F.R.M.S.
FISHER, Edwards, Esq., F.S.A. (Scot.), Fell. Roy. Soc. of Antiq. Irel.
GARNETT, Frederick Brooksbank, Esq., C.B.; Mem. of Counc. and F.S.S.; Mem. Roy. Arch. Inst.; Mem. Cumb. and Westm. Antiq. and Arch. Soc.
GREATHEAD, James Henry, Esq., Mem. of Council and M. Inst. C.E., M. Inst. M.E.
GRIEG-SMITH, James, M.A., M.B., CH.M. (Aberd.), F.R.S.E., Professor of Surgery in University College Bristol; Formerly Examiner in Surgery in the University of Aberdeen.
HUGHES, John, Esq., F.C.S., F.S.S.
HUMPHRY, Sir George Murray, Knt., M.D., LL.D. (Edin.), Hon. SC.D. (Dubl.), F.R.S., F.R.C.S. (Edin.); Fell. of King's Coll., Hon. Fell. Downing Coll., and Professor of Surgery in the University of Cambridge.
IRONS, David Blackwell, Esq., W.S., M.R.S.G.S.
KEENE, Captain Christopher Theodore Pearcy, F.L.S., F.S.S., F.Z.S.
KIDD, George H., Esq., M.D. (Dubl.), Formerly President of the Royal College of Surgeons and Royal Academy of Medicine, Ireland.
LEAROYD, Samuel, Esq., F.G.S.; President of the Litt. and Sci. Soc.; Governor and Past President of the Incorp. Law Soc., Huddersfield.
LE CLÈRE, Captain Felix, M. Inst. N.A.; Naval Attaché French Embassy.
LEVESON-GOWER, Granville William Gresham, Esq., M.A. (Cantab.), F.S.A., D.L., Formerly Vice-President of the Society of Antiquaries.
LYALL, David, M.D. (Aberd.), F.L.S. and Deputy Inspector General of Hospitals.
LYONS-CLEMINSON, James, Esq., M. Inst. C.E., and Inst. M.E., Fell. Roy. Hist. Soc., F.R.G.S.
MAGNUS, Major General John Popham, R.E., R.D.S.
MONTAGU, Hyman, Esq., F.S.A., Vice-President of the Numismatic Society, Mem. Hellenic Soc.
MOUAT, Frederick John, M.D., LL.D. (Edin.), F.R.C.S. (Eng.), Vice-President of the Roy. Stat. Soc., F.R.G.S., Hon. Mem. of the Geograph. Soc. of Berlin; Formerly Professor of Med. and Med. Jurisprudence, Med. Coll. Calcutta, Deputy Inspector General Bengal Army, and Inspector General of Prisons in Bengal.
NORCLIFFE, Rev. Charles Best, M.A., and Fell. Univ. Coll. (Durham).
PENDER, Sir John, G.C.M.G., M.P., F.R.S.E., F.G.S., F.R.A.S., F.S.A. (Scot.), F.S.S.
PURNELL, John James, Esq., F.R.C.S. (Eng.).
RATTRAY, James Clerk, M.D., L.R.C.S. (Edin.), F.R.S.E., F.S.A. Scot.
RENOUF, Sir Peter le Page, Knt., President Soc. of Bib. Arch., Formerly Professor of Ancient History and Oriental Languages in the Catholic Univ. Irel., and Keeper of Egyptian and Assyrian Antiquities in the British Museum.
SAMUEL, Henry Sylvester, Esq., F.R.G.S.
SCHACHT, George Frederick, Esq., F.C.S.; Formerly Examiner and Vice-President of the Pharmaceutical Society of Gr. Brit.
SMITH, Charles Hubert, Esq., M. Inst. M.E.; Surveyor to H.M.'s Board of Trade.
SMITH, Frederick Augustus Alfred, M.D., CH.M. (Glasg.), M.D., Jeff. Med. Coll. (Thila); F.R.G.S.
SOUTHWELL, Charles Henry, Esq., F.R.M.S.
STONEHAM, William Burne, Esq., F.L.S.
TABUTEAU, Lieut.-Colonel Anthony Olivier, F.G.S., and Soc. Geol. de France.
TANNER, Colonel Henry Charles Baskerville, Late Mem. of Counc. and F.R.G.S.
THOMSON, Archibald, Esq., M. Inst. N.A., Vice-President of the Institute of Marine Engineers.
TYLER, Charles, Esq., F.L.S., F.G.S., F.Z.S.; Formerly Vice-President of the Royal Microscopical Society.
VEITCH, John, M.A., LL.D. (Glasg.), F.S.A. (Scot.).
WADE, Sir Thomas Francis, K.C.B., G.C.M.G., Hon. LL.D. and Fell. King's Coll., and Professor of Chinese in the University of Cambridge; Past President of the Royal Asiatic Society; Past Mem. of Counc. of the Royal Geographical Society.
WICKENDEN, Colonel George Thomas, F.R.G.S.
WILSON, Robert, Esq., M. Inst. C.E. and Inst. M.E., F.R.S.E., F.R.G.S.
WILSON, Sir Samuel, F.R.G.S., F.L.S., Fell. Roy. Col. Inst., Formerly M.L.A. and M.L.C. of Victoria (N.S.W.).
There are a number of online references to the Royal Societies Club, either to specific events or lectures held there, or in connection with particular individuals and their membership of this august body, but I have so far been unable to find any sources giving further information about Club itself.