CONTENTS 
OF VOL. 155. 
I. On the Spectra of Ignited Gases and Vapours , with especial regard to the different 
Spectra of the same elementary gaseous substance. By Dr. J. Plucker, of Bonn , 
For. Mernb. B.S. , and Dr. J. W. Hittorf, of Munster page 1 
II. On the Osteology of the genus Glyptodon. By Thomas H. Huxley, F.B.S. . . 31 
III. Investigations of the Specific Heat of Solid Bodies. By Hermann Kopp. Com- 
municated by T. Graham, Esq., F.B.S. 71 
IV. On the Composition of Sea-water in the different parts of the Ocean. By Georg 
Forchhammer, Professor at the University , and Director of the Polytechnic Insti- 
tution at Copenhagen. Communicated by the President 203 
V. On the Magnetic Character of the Armour-plated Ships of the Boyal Navy, and on 
the Effect on the Compass of particular arrangements of Iron in a Ship. By 
Frederick: John Evans, Esq., Staff Commander B.N., F.B.S., Superintendent of 
the Compass Department of Her Majesty's Navy; and Archibald Smith, Esq., 
M.A., F.B.S., late Fellow of Trinity College, Cambridge, Corresponding Member 
of the Scientific Committee of the Imperial Bussian Navy 263 
VI. On some Foraminifera from the North Atlantic and Arctic Oceans, including Davis 
Straits and Baffin's Bay. By W. Kitchen Parker, F.Z.S., and Professor T. 
Rupert Jones, F.G.S. Communicated by Professor Huxley, F.B.S. . . 325 
VII. New Observations upon the Minute Anatomy of the Papillae of the Frog's Tongue. 
By Lionel S. Beale, M.B., F.B.S., Fellow of the Boyal College of Physicians, 
Professor of Physiology and of General and Morbid Anatomy in King's College, 
London ; Physician to King's College Hospital, &c 443 
VIII. A Dynamical Theory of the Electromagnetic Field. By J. Clerk Maxwell, 
F.B.S 459 
