X INTRODUCTION. 



the genus of a plant with greater facility, a Synopsis of the 

 Genera according to that system has therefore been prefixed ; 

 thus, it is hoped, combining to a considerable extent the ad- 

 vantages of both methods. 



In describing the genera and species in the body of the work, 

 I have adopted pretty much the characters of Sir W. J. Hooker, 

 as given by him in his excellent British Flora, it being the 

 book I principally consulted in the examination of my speci- 

 mens, from which I have also taken the etymologies of the generic 

 names. 



The second and not least valuable part of the work contains 

 the Orders, Musci, Hepaticse, and Lichenes, by Doctor Taylor, 

 (the well-known coadjutor of Sir W. J. Hooker in the Muscologia 

 Britannica,) who of all the Botanists of Ireland, was best qualified 

 for the task. It will be seen that he has added a new genus (Hy- 

 drophyte) in the order Hepaticae, and in the order Lichenes a 

 good many hitherto undescribed species, six of which appear 

 in the Addenda. 



W. H. Harvey, Esq. the well-known Algologist, (before his 

 departure to the Cape of Good Hope,) kindly undertook to 

 describe the Algae. This he accomplished from the examina- 

 tion of a full collection in my possession, chiefly formed by the 

 late amiable and accomplished Miss Hutchins, a lady who for 

 many years was unremitting in her investigation of the Botany 

 of the south of Ireland. To these he has added his own numerous 

 discoveries, and those of other Botanists, whose names are men- 

 tioned ; and since his departure I have been fortunate enough 

 to add nine species new to Ireland, communicated by several 

 botanical friends, as will appear in that portion of the work. 



Dublin, 10th May, 183G. 



