vii 



Page 



On the Development of the Skull and its Nerves in the Green Turtle 

 (Chelone midas), with remarks on the Segmentation seen in the Skull 

 of various types. By Professor W. K. Parker, F.B.S 329 



On an Extension of the Phenomena discovered by Dr. Kerr and described 

 by him under the title of " A New Eelation between Electricity and 

 Light." By J. E. H. Gordon, B.A., Assistant Sec. of the British 

 Association 346 



February 20, 1879. 



On Electrical Insulation in High Vacua. By William Crookes, F.E.S 347 



On the Reversal of the Lines of Metallic Vapours. No. IV. By G. D. 

 Liveing, M.A., Professor of Chemistry, and J. Dewar, M.A., F.RS., 

 Jacksonian Professor, University of Cambridge 352 



February 27, 1879. 



Studies in Acoustics. I. On the Synthetic Examination of Vowel 

 Sounds. By William Henry Preece and Augustus Stroh. (Plates 6, 7) 358 



On the Eeversal of the Lines of Metallic Vapours. No. V. By G. D. 

 Liveing, M.A., Professor of Chemistry, and J. Dewar, M.A., F.E.S., 

 Jacksonian Professor, University of Cambridge 367 



List of Presents .• 372 



No. 194.— March 6, 1879. 



Observations on the Physiology of the Nervous System of the Crayfish 

 {Astacus fluviatilis). By James Ward, M.A., Fellow of Trinity College, 

 Cambridge 379 



Preliminary Eeport upon the Comatulw of the " Challenger " Expedition. 

 By P. Herbert Carpenter, M.A., Assistant Master at Eton College 383 



On the Characters of the Pelvis in the Mammalia, and the Conclusions 

 respecting the Origin of Mammals, which may be based on them. By 

 Professor Huxley, Sec. E.S., Professor of Natural History in the Eoyal 

 School of Mines. (Plate 8) 395 



March 13, 1879, 



The Influence of Electricity on Colliding Water Drops. By Lord Eayleigh, 

 F.RS , , 406 



On the Influence of Coal-dust in Colliery Explosions. No, 2. By W. 

 Galloway , 410 



The Contact Theory of Voltaic Action. No. III. By Professors W. E. 

 Ayrton and John Perry 421 



