Stewart — Mollusca of the Boulder Clay. 
169 
CASTLE-ESPIE, COUNTY DOWN. 
Three miles from Comber, on the shore of Strangford Lough, there is an 
extensive deposit of Boulder Clay resting on Carboniferous Limestone, which is 
beautifully polished and striated. Shells are very scarce in the clay. Astarte 
sulcata and a Leda were the only forms recognised. 
CRUMLIN RIVER, COUNTY ANTRIM. 
The Boulder Clay is exposed at several points on the Crumlin River, and 
this locality is remarkable for the occurrence of a small patch, not much over a 
square yard in extent, as far as seen, but crowded with shells of Mytilus edulis 
in a very fragile condition. This bed is exposed on the south bank of the 
river, at about midway between Crumlin and the shore of Lough Neagh. It 
was discovered by Mr. E. T. Hardman, F.G.S., who supposed the shells to 
represent a species of Unio , and the clay to be a lacustrine deposit of Pliocene 
age.* Mr. W. Swanston, F.G.S., has shownf that the shells are really the 
tests of the common mussel, and that the clay is truly glacial. No other shells 
have been found associated with the Mytilus , but Mr. Joseph Wright, F.G.S., 
has found several species of Foraminifera. 
BOVEVAGH RIVER, COUNTY DERRY. 
This bed is situated not far from the village of Dungiven, and was 
described by Portlock in the Report on the Geology of Londonderry, page 159. 
It is only remarkable on account of the occurrence, in a very limited exposure 
of great numbers of Turretella terebra , , a shell that seems to be rare in the 
Boulder Clay elsewhere in Ireland. 
BALLYRUDDER, COUNTY ANTRIM. 
A most interesting glacial bed is to be seen at Ballyrudder, about six miles 
north of Larne, on the road to Glenarm. This deposit was examined long since 
by Dr. Jeffreys and the late Mr. George C." Hyndman, who published, in the 
Report af the British Association for 1859, a list of the shells which they found, 
at the same time intimating that their search was not exhaustive. It has also 
been recently mentioned by Mr. T. Mellard Reade, F.G.S., in Vol. XXXV. of 
* Geol. Mag., Dec. 2. Yol. 3, p. 556. 
+ Geol. Mag., Dec. 2, Vol. 6, No. II. 
