CONTENTS 



MEMOIRS. 



I. Notes on a Collection of Hymenopteia from Greymouth, New 

 Zealand, with descriptions of New Species. By Peter 

 Cameron pp. i — 53 



II. Description of two new species of Mutilla from South Africa. 



By Peter Cameron pp. 1—3 



III. On Waves in a medium having a Periodic Discontinuity of 



Structure. By Horace Lame, M.A., F.R.S pp. 1—20 



— IV. Further Investigations into the Molluscan Fauna of the Arabian 

 Sea, Persian Gulf, and Sea of Oman. (Addendum : Descrip- 

 tion of a New Strombus from the Mekran Coast of Beluchistan.) 

 By James Cosmo Melvill, M.y\., F.L.S. Plates i and 2. 



pp. 1—40 



V. On a Method of Determining the Thermal Conductivities of 

 Salts, with some results of its application. By Charles H. 

 Lees, D.Sc. ... ... ... ... ... ... ... pp. i — 4 



VI. On the Mechanical Equivalent of Heat. By Osuorne Rey- 

 nolds, M.A., F.R.S., and W. H. Moorbv, M.Sc. ... pp. i — 54 



VII. On the Instantaneous Pressures produced on the Collision of 

 Two E.xplosion Waves. By R. H. Jones, B.Sc, and J. 



Bower, B,Sc. Plates PP. i — 7 



VIII. On a General Method of determining the Form of the Velocity- 

 Potential of Fluid- Motion in Two Dimensions across a 



Channel with Straight Sides. By R. F, Gwyther, M.A. pp. i — 6 



IX, On the Velocity of Sound in a Tube, as affected by the 

 elasticity of the Walls. By Horace Lamb, M.A., F.R.S. 



pp. I — 16 



X. The New (iold Discoveries. By Eduard .Suess, of Vienna, pp. i — 9 



XI. Ilymenoptera Orientalia, or Contributions to a Knowledge of 

 the Ilymenoptera of the Oriental Zoological Region. Part 

 VII. By Pi-.ter Cameron. Plate 4 pp. 1—84 



XII. On the Physical Basis of Psychical Events. (The Wilde Lecture.) 



By Professor Michael Foster, Sec. R.S. pp. i - 46 



XIII. Contributions to our Knowledge of the Marine Fauna of the 



Falkland Islands. By Edith M, Prat'J', B.Sc. Plate 5. pp. 1—26 



