ADVERTISEMENT. 



In drawing up the following characters of those Fossils of the Irish Carboniferous Series whicli 

 I have myself seen, I have endeavoured to express, first, all those characters which seemed 

 permanent, or of specific value, in each species ; second, the principal varieties to which they 

 are liable ; and finally, to point out, when necessary, the distinctions between the nearly allied 

 species. The Genera have been placed in accordance with their affinities, commencing with 

 the most highly organized ; the Species have been arranged in alphabetical order under each 

 generic head, to facilitate reference. 



I have not noticed either the geological or geographical localities of the species, as from 

 having examined and named the Collections made by Mr. Griffith, from nearly every carbonife- 

 rous district in Ireland, the lists are so extensive that it has been thought better to keep them 

 distinct. 



The Collections of Fishes and Plants, although large and interesting, have not, as yet, been 

 sufiiciently examined for publication. 



With regard to the drawings, I have spared no pains to make them as accurate as possible; 

 a large number are entirely from my own pencil, and the others have been most carefully cor- 

 rected, both as to outline, measurements, and effect, by my own hand. 



Since the following Synopsis was sent to Pi'ess, and a large portion of it printed off", I 

 received Koninck's " Descriptions des Animaux Fossiles," &c., Parts I. to XII., and althougli 

 from the relative positions of the carboniferous deposits of Ireland and Belgium, an almost 

 perfect similarity might be expected in their organic remains, yet of the large number of new 

 fossils here put forward, the following only seem identical with M. de Koninck's species: — 

 The Nautilus hexagonus, De Kon., is the Nautilus (Discites) planotergatus of this work, 

 but as there is already a Nautilus hexagonus in tlie middle Oolite, the name I have proposed 

 may perhaps be adopted. One of the varieties of the Solarium fallax, De Kon., is my Pla- 

 tyschisma zonites ; as there are, however, two distinct forms confounded by that author, my 

 specific name may, perhaps, be retained for this species, and thus the term /a//a.r be limited 



