1906. StkIvFOx.— Z. & F. W. Mollusca of N. IV. Donegal 67 
The shell-pockets in the dime areas are extremely abun- 
dant, but as many of the shells may be derived from older 
deposits, these have been listed separately from the live 
records. I have to thank C. Oldham and Dr. Chaster for 
looking over the Pisidia and some other species. 
Belfast. 
2. ROSGUIIvL PENINSULA AND ShEKPHAVEN DUNKS. 
BY R. WKI<CH, M.R.I. A. 
Like Horn Head, the little peninsula of Rosguill may have 
been an island or rather a group of islands in recent geological 
times. Lying between Sheephaven and the long narrow 
Mulroy inlet, it is now connected with what might be called 
its mainland by a low sandy neck, almost covered by high 
spring tides, except on the western side. Here there are high 
sand dunes fringing the great strand — Tramore — on Sheep- 
haven. The south end of the peninsula is formed mainly of 
quartzite and schistose rocks, very rugged and bare, rising in 
Ganiamore Mountain to 682 feet ; indeed most of this portion 
is over 200 feet high. The northern part is connected with 
this by a great sand flat, over half a mile wide and only a few 
feet above the sea over its entire area. The rocks here are 
mainly granite, which has intruded into the metamorphic 
rocks, Magherachullion Mountain (544 feet) showing the line 
of contact clearly from bottom to top. Most of the areas 
mentioned would be very poor collecting ground, were it not 
for their very rugged character. Useless for tillage purposes, 
they contain masses of loose rocks, with a fair amount of food 
plants — good shelter for the land mollusca. The mossy 
areas of the sand dunes are the homes of immense numbers of 
some xerophile species, with Vihina and Helix pulchella. 
Considering its size, Rosguill has a fair number ol fresh- 
water species. Melmore Lough is the largest water area, an 
L-shaped lake in a deep hollow at the foot of a mountain, 
that is being filled up by drifting sand, blown in through the 
Murder Hole by westerly winds from the open Atlantic. This 
lake looks as if it had filled this extensive hollow at one time. 
Close to Rosapenna hotel is a very shallow lakelet on the sand- 
flat at Trabeg, and these, with a few very small ponds of peaty 
