194 Proceedings of the Royal Irish Academy. 



distribution of Irish Lichens is due to their investigations. In Jones's two 

 lists 78 new species are recorded, in addition to those given in " Flora 

 Hibernica," His collections are now housed in the National Museum. 

 Hardly less important than their work was that of Dr. David Moore, as a 

 reference to the pages of Leighton's "Lichen Flora of the British Isles," 

 published in 1871, will show. In 1878 a list of 150 species found in the 

 counties of Dublin and Wicklow was published by Mr. Greenwood Pirn, in 

 connexion with the British Association's visit to Dublin. In the folio wins; 

 year the 3rd edition of Leighton's " Lichen Flora " appeared, in which were 

 incorporated numerous discoveries of new species made in the neighbourhood 

 of Kylemore, by Mr. Charles Larbalestier — a name wdiich deserves to rank 

 along with those of Carroll and Jones. 



The 3rd edition of Leighton's Flora was, like its predecessors, supposed 

 to contain aU known Irish localities ; but, as a matter of fact, many species 

 previously recorded as Irish were overlooked. 



A considerable number of Irish species, with their localities, will be found 

 in the papers of Leighton and Crombie enumerated at the end. The latter's 

 British Museum Catalogue, Part L, published in 1894, contains many Irish 

 references. 



The most recent papers on Irish Lichens are one by Lett, containing a 

 list of 74 species occurring in the Mourne Mt. District and published in 1890, 

 and another, which is a short list of 14 species found by McArdle in Lambay, 

 and published in 1907. At the present time nobody seems to be working 

 seriously at the study of Irish Lichens, although the western part of the 

 island probably contains a number of hitherto undescribed species ; and the 

 group presents some very interesting problems in geographical distribution. 



Olivier's " Lichens d'Europe," of which the first part has been published, 

 contains many Irish localities. 



Sub-divisions of the Country. 



The sub-divisions employed are those which I proposed in the Irish 

 Naturalist for August, 1908, and January, 1909. These will be seen at a 

 glance on the accompanying map. Each of the four provinces is divided into 

 three sub-provinces. The first letter of each province is used as an 

 abbreviation for the name of that province, while the sub-pro\dnces are 

 indicated by the figures i, 2, 3, appended, the figure i in each case referring 

 to the sub-province which extends furthest south, the figure 3 to that which 

 extends furthest north, while the intermediate sub-province is indicated by 

 the figure 2. Thus a species occurring in Co. Dublin is indicated by the 



