Royal Society. 289 



botanists," and given in their place a very complete account of the 

 geographical distribution of the plants. 



We have made much use of this volume, and can recommend it 

 confidently to all botanists as being a very complete and critical 

 flora of Ireland. Much care has been taken and sound judgment 

 exercised in deciding upon what species are to be considered as 

 native and what as introduced into Ireland ; and the authors have 

 stated their reasons for the exclusion or omission fully in each case. 



PROCEEDINGS OF LEARNED SOCIETIES. 



ROYAL SOCIETY. 



February 21, 1867. — Dr. W. A. Miller, Treasurer and Vice-President, 

 in the Chair. 



" A brief Account of the * Thesaurus Siluricus,' with a few facts 

 and inferences.'* By J. J. Bigsby, M.D. 



I have been led to attempt the preparation of a general view of 

 Silurian life, as far as now known, by my own frequent want of 

 such a record or muster-roll of the constituent members of this great 

 initiatory division of palaeozoic zoology, — a task which has been made 

 pleasant by some personal knowledge of two countries rich in the 

 earher formations. 



I have been further encouraged by the great accumulations of 

 the last few years, through the establishment in North America and 

 elsewhere of numerous colleges, each of them having become the 

 centre of more or less field-work. Far more aid still has been 

 derived from many public surveys on a tolerably liberal scale. Nor 

 can we forget the highly meritorious and successful labours which 

 have been, and still are, carried on by private individuals in almost 

 every part of Europe and North America. 



As this undertaking required an exactitude and a critical skill in 

 determining species and genera according to late improvements in 

 classification, much beyond an ordinary acquaintance with Silurian 

 life, after my materials were put together, I obtained the very 

 valuable aid of Mr. J. W. Salter, late Palaeontologist at the London 

 Museum of Practical Geology. 



I was then, through the kindness of Sir Roderick I. Murchison, 

 Bart., allowed to submit my manuscript to Robert Etheridge, Esq., 

 F.R.S.E., the present Palaeontologist to the Institution over which 

 Sir Roderick presides. 



To the careful superintendence of these two eminent naturalists 

 I am indebted for corrections and suggestions of the greatest im- 

 portance, and particularly as relates to Britain and to Europe gene- 

 rally. 



My matter has been principally found in the voluminous and 

 truly priceless writings of Murchison, Sedgwick, Barrande, Sowerby, 

 De Verneuil, James Hall, M'^Coy, Salter, Billings, Angelin, Eichwald, 



