THE TRILOBITES 



CARBONIFEROUS LIMESTONE, 



INTRODUCTION. 



Considerable confusion has hitherto existed in the nomenclature of the various 

 species of Trilobites from the Carboniferous Limestone series, partly arising from 

 the fact of the very near affinities actually existing between the genera of Phil- 

 Upsia and Griffithides, partly from the too often fragmentary condition of the 

 specimens obtained, but also largely due to the unsatisfactory figures which 

 accompany the descriptions of most of the early writers on the fossils of this 

 group. 



Thanks to the labours of Portlock, M'Coy, Valerian von Moller, Traquair, and 

 others, many of the difficulties to a classification of these, our latest Trilobites, 

 have been removed, and much help affiarded in the task of unravelling the tangled 

 skein of synonymy woven by Russian, German, French, Belgian, English, and Irish 

 palaeontologists during the past sixty years. 



I have given, in the following pages, in chronological order, short notices of 

 the principal works in which the species of Carboniferous Trilobites have been 

 referred to, and in the subsequent descriptions I have attempted, to the best of my 

 ability, to affix to each its proper generic and specific place. 



I should but ill fulfil my duty were I to omit to return thanks to the many 

 friends who have assisted me with the loan of specimens for this Monograph ; 

 notably I would mention Prof. T. McKenny Hughes, M.A., F.G.S., Woodwardian 

 Professor of Geology in the University of Cambridge, who has most hberally 

 placed the whole of the extensive series of Carboniferous Trilobites belonging to 

 the Woodwardian Museum in my hands for examination and figuring. 



I am equally indebted to Prof. A. Giekie, LL.D., F.R.S., F.G.S., Director- 

 General of the Geological Survey of Great Britain and Ireland, and Prof. Edward 



