PREFACE. 
Again the pleasant task recurs of thanking my friends for their 
encouragement and assistance ; my only regret being, that the num- 
ber of contributors to thank is less than heretofore. Those wlio 
have lightened by their contributions the labour which otherwise 
would have devolved on myself, have, during the past year, done 
me real service. 
The papers and letters by my friends Mr. Du Noyer, the Eev. 
Hugh Mitchell, the Eev. Gilbert M. Smith, Mr. Meyer, of Guildford, 
Mr. Blake, Mr. James Powrie, Mr. Davies, the Eev. "VV. S. Symouds, 
Professor Eupert Jones, Mr. Simons, Professor AV. King, Mr. Lech- 
mere Guppy, Mr. T. Grindley, Dr. Leslie, Mr. J. D. Sainter, Mr. 
James Plant, of Leicester, Mr. S. E. Pattison, Professor Ansted, 
Eev. O. Fisher, Mr. E. E. Lankester, Mr. Binney, of Manchester, 
Count Marschall, Mr. S. P. Woodward, Mr. H. C. Sorby, Dr. Black- 
more, Mrs. Strickland, Lieut.-Colonel NicoUs, Mr. Harrison, of 
Melbourne, and Mr. Drake, are especially worthy of my best ac- 
knowledgments. The names of some respected former contributors 
are absent from this list, but the friendship between them and my- 
self continuing unbroken, welcome communications from them will 
most likely grace our future volumes. For my own part, the pres- 
sure of many important labours prevents such entire devotion to 
geology as I should like to give ; but as far as my power permits, 
