Vegetation Committee's Excursion to Ireland. 257 
Bog Succession. 
Molinia- bog. 
I 
Rhyuchospora-bog. 
I 
Reed-Swamp. 
I 
Submerged aquatic 
vegetation. 
Rocky Knoll and Hillside 
Succession. 
Oak-birch wood. 
Heath-pasture and Heather- 
moor with Ericaceae and 
Ulex Gallii. 
Some comparisons may he made between the moorlands of 
Connemara and similar tracts of country in the N.W. Highlands, 
the Hebrides and the Shetlands. In these Scottish areas Scirpus 
ccespitosus dominates the most characteristic association. In N.W. 
Sutherland, the flat basaltic plateau of Northern Skye, and the 
valley floors and gently sloping hillsides of Shetland, this type 
remains dominant over many hundred square miles, associated with 
Eriophorum vaginatum, stunted Calluna, Erica Tetralix, Narthe- 
cium ossifragum, and Sphagnum, with mounds of Racomitrium 
lanuginosum in drier places. 
In the western portion of N. Uist the Scirpus ccespitosus 
association extends over hills of low elevation and broad shallow 
valleys, while hills in the eastern part of the island of similar 
altitude and character to Ben Lettery support an association 
dominated by Calluna and Eriophorum vaginatum. The Rhyn- 
chospora type of bog does not appear to be a marked feature in any 
of these Scottish areas. The difference in character between the 
surface of the moors in Connemara and districts in N.W. Scotland, 
such as the borders of Caithness and Sutherland north of Forsinard, 
is very striking. Both districts are covered with a very similar 
vegetation, but while the Irish area presents an almost unbroken 
surface, the Scottish moors are traversed by deep channels often 
cut eight or ten feet into the peat. On the Connemara moors peat 
appears to be forming rapidly at the present time, but in Shetland, 
Caithness and Sutherland, with many parts of the Outer Hebrides, 
denudation appears to be more rapid than growth. Passing farther 
north, peat-formation appears to have almost ceased in the west 
and south of Iceland, for whilst the upper layers of peat contain 
much Scirpus, the moors are now covered with two or three feet of 
fine dust supporting a much drier type of vegetation. 
Sand-Dunes and Shore Plants. 
The sand-dunes of Dog’s Bay, south-west of Roundstone, were 
of some interest. As is so often the case in a country of hard rock 
they formed an isthmus connecting a rocky “ island ” with the 
mainland. The dunes themselves were largely formed of the tests 
of Foraminifera, and at intervals were Neolithic kitchen-middens 
composed of the shells of Patella, etc. From the physiographical 
and ecological standpoint, the dunes were of a degraded type, having 
suffered much denudation. The surface was largely bare, and bore 
some Triticum junceum but no Psamma arenaria, except a few 
little tufts remaining on the tops of some of the hummocks. The 
whole isthmus has evidently passed through the stage of turfy fixed 
