CONTENTS. 
PART III. 
XV. On a Class of Invariants. By John C. Malet, M.A., Professor of Mathe¬ 
matics, Queen’s College, Cork. Communicated by Professor Cayley, LL.D., 
F.P.S. .page 751 
XVI. Description of portions of a Tusk of a Proboscidian Mammal (Notelephas 
australis, Owen). By Professor Owen, C.B., F.P.S., &c .777 
XVII. Memoir on the Theta-Functions, particularly those of two valuables. By A. It. 
Forsyth, B.A., Fellow of Trinity College, Cambridge. Communicated by 
Professor A. Cayley, LL.D., F.P.S. ..783 
XVIII. On Seismic Experiments. By J. Milne, F.G.S., and T. Gray, B.Sc., 
F.P.S.E. Communicated by A. C. Ramsay, LL.D., Director-General of the 
Geological Survey, and of the Museum of Economic Geology . 863 
XIX. Report of an Examination of the Meteorites of Cranbourne, in Australia; of 
Rowton, in Shropshire; and of Middlesbrough, in Yorkshire. By Walter 
Flight, D.Sc., F.G.S., of the Department of Mineralogy, British Museum , 
South Kensington. Communicated by H. Debus, Ph.D., F.R.S. . . . 885 
XX. On the Development of the Ossicida auditus in the Higher Mammalia. By 
Alex. Fraser, M.B., dec., The Owens College, Manchester. Communicated by 
Dr. Allen Thomson, F.P.S . 901 
XXI. Contributions to the Anatomy of the Central Nervous System in Vertebrate 
Animals. By Alfred Sanders, M.R.C.S., F.L.S., formerly Lecturer on 
Comparative Anatomy at the Ijondon Hospital Medical College. Communi¬ 
cated by Professor Huxley, LL.D., F.P.S. . 927 
XXII. On the Influence of the Galvanic Current on the Excitability of the Motor 
Nerves of Man. By Augustus Waller, M.D., and A. de Watteville, 
M.A., B.Sc. Communicated by Dr. Burdon-Sanderson, F.P.S. . . . 961 
