MOSSES, HEPATIOE AND LICHENS. 191 



possibly it may not be uncommon in this island. The occur- 

 rence of these two essentially Irish hepatics in Guernsey is of 

 great interest and is moreover very suggestive. There are 

 still a good many species which I have every reason to believe 

 will be found here, although up to the present my search for 

 them has been fruitless ; but then in the matter of Hepaticoe 

 it cannot be said that he who runs may read, and only by 

 assiduous investigation of every likely nook and cranny can 

 we hope to bring to light these tiny gems of plant life. No 

 record of the Hepaticce of Guernsey has ever been published. 



That the Lichen-Flora of this island is a rich and varied 

 one will be evident by a glance at the following list, which 

 comprises considerably more than one-fifth of the entire 

 number of species (exclusive of varieties and forms) recorded 

 for the whole of the United Kingdom. Saxicolous species of 

 course predominate, especially such as are peculiar to mari- 

 time districts; whilst those which grow on wood, whether 

 trees or dry timber, are much less strongly represented. It is 

 however to be noted, that many lichens which are normally 

 lignicolous, are to be found here growing on rocks. Abundant 

 employment for hammer and chisel will be found among the 

 stupendous rock-masses and scattered boulders which beautify 

 our southern coast, for generally speaking it is impossible to 

 lay one's hand on the exposed face of a rock without covering 

 a lichen; but many of the stones are excessively hard, and 

 will frequently put the temper of both the collector and his 

 chisel to a severe test. 



And here I would impress upon the young student the 

 imperative necessity of testing, both chemically and micro- 

 scopically, every specimen he collects before placing it in his 

 herbarium. It is an utter waste of time to attempt to identify 

 a Lecidea or a Lecanora by external characters alone; even 

 for a practised hand it is seldom safe, and I have known 

 experienced lichenologists make most grievous blunders 

 through this hasty and careless method of jumping at con- 

 clusions. Some of the foliaceous species, again, are so exactly 

 similar as to be indistinguishable except by the employment 

 of chemical re-agents; whilst in an enormous and unwieldy 

 genus like Lecidea, comprising as it does some 400 British 

 species, the very first step towards identification is an exam- 

 ination of the spores. 



In order to render this paper as complete as possible, I 

 have inserted in the list a number of species not as yet 

 detected by me, but recorded for Guernsey in Leighton's 

 Lichen Flora of Great Britain, Ireland and the Channel 



