2 CARBONIFEROUS TRILOBITES. 



Hull, M.A., LL.D., F.R.S., Director of tho Irish Branch, for permitting me the same 

 opportunities of studying and figuring the beautiful type-series of forms out of the 

 Jermyn Street Museum and the Museum of the Geological Survey in Dublin. To 

 Dr. R. H. Traquair, F.R.S., the Rev. E. 0. de la Hey, John Aitken, Esq., Joseph 

 Wright, Esq., and my kind friends in Glasgow, Messrs. John Young, James 

 Thomson, Robert Craig, J. Smith, and others, who have so wilHngly entrusted 

 me with the choice specimens from their private collections for my work, I am 

 especially thankful. 



In a table further on, I give a list of the Divisions of the Carboniferous series 

 of deposits as recognised in England, Scotland, and Ireland, in compiling and 

 preparing which I am indebted to the kindness of my colleagues, the Messrs. R. 

 Etheridge (father and son) ; also to Mr. Robert Etheridge, jun., for much valuable 

 assistance in preparing the accompanying Bibliography. 



