CONTENTS OF VOL. XXV. — FOURTH SERIES. V 



Page 

 Prof. Harkness on the Skiddaw Slate Series ; with a Note 



on the Graptolites by Mr. J. W. Salter 235 



Prof. T. R. Jones on Fossil Estherite, and their Distribution. 235 

 Dr. Dawson on the Flora of the Devonian Period in North- 

 eastern America 235 



Mr. T. Davidson on the Lower Carboniferous Brachiopoda 



of Nova Scotia 236 



Mr. T. Curley on the Gravels and other superficial Depo- 

 sits of Ludlow, Hereford, and Skipton 236 



Messrs. G. E. Roberts and J. Pvandall on a Northerly Ex- 

 tension of the Upper Silurian ' Passage-Beds ' to Linlev, 



Salop .*. 236 



Mr. G. E. Roberts on some Crustacean-tracks from the Old 



Red Sandstone near Ludlow 237 



Prof. Jamieson on the Parallel Roads of Glen Roy 237 



Mr. W. B. Dawkins on a Hyaena- den at Wookey Hole, 



near Wells 237 



Mr. J. W. Salter on the discovery of Paradoxides in Britain. 238 

 Dr. Wright on the Fossil Echinidce of Malta; with Notes 

 on the Miocene Beds of the Island, by A. Leith Adams. 238 

 On the Determination of the Wave-length of the Ray A, by 



M. Mascart , 238 



On a New Form of Spectroscope, by Dr. Wolcott Gibbs ...... 240 



NUMBER CLXVIII.— APRIL. 



Dr. Mayer on Celestial Dynamics 241 



M. Viktor von Lang on the Crystalline Form and Optical Pro- 

 perties of Sulphate of Thallium 248 



M. G. Kirchhoff on the History of Spectrum Analysis and of 



the Analysis of the Solar Atmosphere 250 



Prof. Tait's Reply to Prof. Tyndall's Remarks on a paper on 



" Energy " in 'Good Words ' 263 



Mr. S. M. Drach on the Polyhedric Fan 266 



Mr. S. V. Wood on the Events which produced and terminated 

 the Purbeck and Wealden Deposits of England and France, 

 and on the Geographical Conditions of the Basin in which 



they were accumulated. (With a Map.) 268 



Mr. C. K. Akin on the Compressibility of Gases 289 



Notices respecting New Books : — The Rev. T. R. Birks on 



Matter and iEther, or the Secret Laws of Physical Change. . 300 

 Proceedings of the Royal Society :■ — 



Prof. Miller on the Photographic Transparency of various 

 Bodies, and on the Photographic Effects of Metallic and 

 other Spectra obtained by means of the Electric Spark. 304 

 Prof. Stokes on the Long Spectrum of Electric Light. . . . 310 

 Prof. Hennessy on the Simultaneous Distribution of Heat 



throughout superficial parts of the Earth 311 



Mr. G. Boole on the Theory of Probabilities 313 



