144 



The Irish Naturalist, 



December. 



from Comber covering an area of about two square miles, mostly on the 

 north side of the estuary of the present river. It represents the delta 

 at the mouth of an overflow channel from the old glacial " Lake Belfast " 

 of the Geological Survey memoir, and is to be correlated in time with the 

 iLisburn esker, the Malone sands and clays, and the " dry gap " of Holy- 

 wood. Haw Hill and Island Hill are to be regarded as the summits of 

 " drumlins " of the earlier typical boulder clay of the district protruding 

 through this later glacial deposit which is banked up against their sides. 

 Narrowing the investigation to the area lying between the levels of the 

 highest and lowest tides, he traced the effect of the estuarine conditions 

 on the vegetation of that limited area which is occupied by typical salt 

 marsh vegetation. The salt marsh plants, owing to the conditions of 

 life under which they exist, exhibit a desert facies, and adaptations to 

 these conditions, profoundly modify the root and leaf systems of the plants. 

 The pioneer plant in the Comber estuary is the Glasswort (Salicornia), 

 of which two species were described. As the level of the land rises other 

 plants make their appearance, notably the grass Glyce.ria maritima, which 

 forms a compact sward in which many of our most beautiful seaside 

 plants find a congenial home. A short account was given of the for- 

 mation of a salt marsh with its accompanying drainage channels and 

 " saltpans." The Festuca meadow in the Comber estuary is replaced 

 at higher levels by closed associations of Juncus maritimus or Scirpus 

 ynaritimus. Where the water becomes fresher owing to drainage from 

 the glacial gravels by which the estuary is surrounded, the reed grass 

 {Arundo Phragmites) makes its appearance, and the lecture closed with 

 a comparison of the Comber salt marsh with other salt marshes in the 

 north-east of Ireland. The lecture was illustrated by a series of lantern 

 slides, maps, and specimens of the plants discussed. 



After a few remarks by the Hon. Secretary (A. MT. Cleland), I. A. S. 

 Stendall, M.B.O.U., and the Rev W R. Megaw, B.A., the proceedings 

 terminated with the election of twelve new members. 



DUBLIN NATURALISTS' FIELD GLUB. 



November io. — The Vice-President in the chair. P. B. Roberts gave 

 a paper with lantern illustrations on " Protective Devices in Butterflies 

 and Moths." The paper opened with a brief outline of the life history 

 of lepidoptera, emphasising the degree of activity, and other qualities 

 affecting the preservation, and the dangers of each stage. The young, 

 it was pointed out, were in high numerical ratio to the mature individuals, 

 and, therefore, late stages needed most careful protection. Protective 

 devices were discussed under the heads of devices with obliterative or 

 hiding, and aggressive purpose. Stress was laid on the application of the 

 methods under field conditioris, and also on such points as the breaking 

 up of outline, and prevention of a flat appearance, in obliterative methods. 

 Finally a brief survey of habits, in connection with self-protection \yas 

 given, and an attempt was made to compare the relative values of various 

 means of protection. 



