144 Guide to Belfast. 



V. maura ll'a/i/.— On rocks exposed to the action of 

 the tide, Ardglass. 



V. plumbea Ac/i. — On calcareous rocks near Belfast. 



V. litoralis Tay/. and V. terebrata {Mudd). — On 

 rocks at Glenarm. 



V. rhyponta Ach. — On the smooth bark of young trees 

 of Pop'ar, Alder, etc. Also often occurring as minute 

 niaculje on the thallus of Graphis scripta. Deer Park at 

 Glenarm. 



References. — Taylor, in Flora Hibernica, 1836 ; Leighton, Lichen 

 Flora of Great Britain and Ireland, 1879 ; Lett, Mosses and Lichens of 

 Mourne Mountains [Proc. R. LA. , 1889); Crombie, British Lichens, 

 vol. i, 1894. 



C. H. W. 



ALG^. 



Marine Alg/e. 



The extensive and chequered coast-line of Antrim and 

 Down affords exceptionally good opportunities for study- 

 ing this beautiful and interesting group of plants. Fifty 

 years ago the brilliant researches of Templeton, Drum- 

 mond, Thompson, Harvey, and McCalla attracted much 

 attention, and by their work they laid a sure foundation for 

 future workers ; and recently, through the work of Mr. 

 Holmes and Mr. Batters, much has been added to our know- 

 ledge of this group. The Olive-brown Seaweeds, including 

 the kelp-weeds and the many varieties of wracks, have long 

 attracted attention, because of the associated kelp industry, 

 still carried on along various parts of the coast. It is not 

 sufficiently well known by those engaged in this industry, 

 that not only are Oar-weeds or Laminarians the most valu- 

 able weeds to burn in preparing the best kelp, but, also, 

 that the wracks are useless, and if used they reduce the 

 market value of the kelp so prepared very materially. The 

 Red Seaweeds include the Corallines, which are used as 

 manure in some districts, owing to the carbonate of lime 

 and potash which they contain. Another point concerning 

 the Green Seaweeds of economic interest is the role many 

 of these seaweeds seem to play when associated with decay- 

 ing organic matter in certain districts, especially near densely 



