Knowles — The Maritime and Marine Lichens of Howth. 95 



Ramalina Curnowii was only seen on the south-west coast, where it grew 

 in tufts dotted irregularly here and there amongst the plants of Ramalina A. 

 on the upper edge of the cliffs between Old Boat-liouse and Drumleck Point. 

 Some of the plants gave the B. scopulorum reaction, and should perhaps 

 be referred to var. armorica of that species ; but they are identical in form, 

 etc., with Ramalina Curnowii. 



R. sithfarinacea is confined to the coast near the neck of the peninsula 

 and occurs both on the Sutton and Howtli sides. At Sutton it grows on 

 rocks cropping out from the soil at some little distance from the sea near 

 Martello Tower associated with Lecanora glaucoma, Rhizocarpon geograpMcum, 

 Parmelia saxatilis, and Evernia 2M'unastri; this last species I have not encountered 

 on a rocky substratum elsewhere on these coasts. On the Howth side 

 R. subfarinacea was much more abundant. The rocks both above and below 

 the Cliii- walk between Casana and Kilrock were studded with small tufts of 

 this species growing amongst Parmelia perJata, P. saxatilis, P. phi/sodes, and 

 other foliaceous licliens. It also occurred but less abundantly, with Lecanora 

 glaucoma, Rhizocarpon geographicum , and L. polytropa. R. subfarinacea seems 

 to prefer shady and rather moist situations. The largest plants were 

 gathered from the steep face of a rock which was shaded and sheltered by 

 Bracken and tall grasses, and were associated with very luxuriant and 

 sparingly fertile plants of Ramalina C 



Although the Ramalina vegetation has not been previously described in 

 detail from any particular locality, it has been referred to by Warming (29) 

 and Ostenfeld (22), and its position on the coast has been more or less 

 defined. In his account of the " Coast-elifP plant-formation " of the Faeroes, 

 Ostenfeld mentions among the litliophyta of that formation the " Grrimmia- 

 Weissia Association " and the " Ramalina Association " as forming two zones 

 on the cliffs, the latter being nearer the sea. He also reproduces a photo- 

 graph by F. Borgesen of the "Coast-cliff plant-formation at the Skanse, in the 

 vicinity of Thorshavn," in which Ramalina scopulorum and Placodium sp. are 

 shown as the dominant species. Warming's Ramalina scopulorum belt has 

 already been referred to, page 83. It evidently corresponds with Ostenfeld's 

 Ramalina Association. 



The Subvegetation of the Ramalina Belt.— From top to bottom of the 

 Ramalina belt, where the growth is not so dense as to exclude too much 

 light and air, numerous foliaceous and crustaceous licliens often find shelter 

 amongst the tufts of the Ramalina fronds. Some, such as several of the 

 Parmelias, Physcia aquila, Buellia canescens, Lecanora atra, L. glaucoma, 

 Rhizocarpon geographicum, and many others, push their way towards the 

 shore, and others, such as Physcia parietina, Placodium lobulatum, Lecanora 



SCIENT. PROC. R.D.S., VOL. XIV., NO. VI. P 



