ijo 



The Irish Naturalist, 



August, 



were AtripleXy Suceda, Lepigonufu medium, and Aster, all in 

 comparatively small quantity. Terns were here in numbers, 

 with a nest every yard along the circular fringe of sea- 

 weed that marked storm-level. After a halt for lunch at 

 Ringhaddy, we went on to the " Gull Rock of Dunsy," off the 

 east shore of Dunsy IvSland, whose fauna consisted of a cloud 

 of Terns and ten baby Mergansers, and the flora of a forest of 

 G. festuccBformis. Thence to Dunsy Rock, where our grass 

 grew in a broad band thirty feet wide, looking like a waving 

 field of corn two feet in height. From Duns}^ we directed our 

 course to Black Rock; off Ringdufferin, recognizable afar by 

 the cloud of Terns hovering over it. Here G. festuccBformis 

 was in still greater profusion, and particularly fine. The 

 normal succession of maritime plants, which we had already 

 observed on other islets, was here conspicuously displayed. 

 First the zone of G. festucaformis. Above that the maritime 

 Atriplices, and above that again Agropyron repens. From 

 Black Rock we went to Dunnyneill. Here there are two islets, 

 more elevated than any we had visited. Our skipper, Hamilton 

 Gilmore, predicted that the grass would not be here, and he 

 proved to be correct. These Strangford islets, though their 

 names frequently end in "Rock," are banks of tough red 

 Boulder-clay. On the larger or higher islands, sufiicient 

 material is present to form by attrition a gravel-beach of some 

 little depth. On this substratum Glyce?ia festuccFfo7jms does 

 not grow. What it likes is an inch or two of stones resting on 

 the drift. This it gets in many places on the mainland and 

 the smaller islands. The islets which were in possession of 

 this grass were all of the same character — low enough to be 

 washed during winter storms, with a thin layer of gravel 

 intermixed with boulders, lying on the Boulder-clay. Dunny- 

 neill, with its gravelly shore and high interior, is thus unsuit- 

 able, and even the absence of cattle does not induce the plant 

 to put in an appearance. 



Next morning we left Killyleagh early. It was dead calm, 

 with a thick mist on the water ; there was not a sound save 

 the occasional splash of a fishing Tern, and we crept silently 

 up the Quoile to Swan Rock, alias Rat Island, lying north of 

 Gore's Island, and near the islet on which I found such 

 quantity of G. festuccBformis last year. I^ike the latter island. 



