10 12 Proceedings of the Royal Irish Academy. 



Floras of Adjolskg Islets. 

 The Bills. 



The Bills are a group of rocks lying close together, 9 miles north-west 

 of Clare Island, and 8 miles S.S.E. of Achill Head. There are two large 

 rocks, each with an area of about a couple of acres, and several small ones, 

 which are mere pinnacles. All rise precipitously from deep water, and attain 

 a general elevation of 100 to 120 feet above Ordnance datum. They are 

 formed of metamorphic rock: and traces of drift, including much-rounded 

 pebbles, are to be seem 



On the north side the rocks go straight down into 20 fathoms. On the 

 south side a small 6- to 8-fathom bank extends. All round the prevailing 

 depth is about 24 fathoms. 



The flora of the Bills is extremely limited. We explored only the eastern 

 or inner rock ; but it has much more vegetation than the western one, and it 

 is unlikely that a landing on the western rock would have resulted in any 

 additions to the flora. The lower limit of vegetation ranges from 100 feet at 

 the western end of the western island to about 50 feet at the eastern end of 

 the eastern one. The cliffs and steep slopes rising from the sea are occupied by 

 luxuriant Beta maritima and Gochlearia officinalis and AtripUx hastata. The 

 top of the inner rock presents an undulating surface, about two acres in 

 extent, of light, springy turf, composed almost entirely of dead Armaria 

 maritima. Its surface is largely bare, studded with numerous great bosses of 

 the same plant alive — some of the bosses being a yard across. Hollows are 

 occupied by colonies of Atriplex hastata, and patches of Festuca ovinia are 

 abundant. The only other plant seen was Speraidaria rwpestris, growing 

 sparingly in rock-chinks. The turf is absolutely riddled with the tunnels of 

 the Puffins, which, with gulls, Guillemots, and Razorbills, are responsible 

 both for the large proportion of bare ground and for the luxuriance of 

 vegetation where it occurs. 



No mosses or hepatics were seen, but lichens were abundant on the rocks, 

 though few in number of species (see Part 14). 



Mweelaun. 



Mweelaun More and Mweelaun Beg He close together two miles south 

 of Clare Island, in the channel. They are formed of sandstone. The smaller 

 rock is entirely wave-swept : the larger has an area of 4 acres, and a height 

 r >f 77 feet above Ordnance datum. The seaward two-thirds is swept quite 



