374 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 
rocks composed of soft calcareous schists, with subordinate harder 
quartzose schists. The latter are most fully developed towards 
the south-west on the Kintyre coast, between Stronchullin and 
Slatefield, decreasing generally to the north-east. The islands 
belong to the latter zone. From Liath Eilean (the light-blue 
isle), near the mouth of Loch Gilp, we exhibit a piece of quartzose 
micaceous schist, showing false bedding, or perhaps foliation lines, 
and with an introduced vein containing chlorite. The mass of 
this island consists of epidiorite, an altered basic igneous rock, 
probably intrusive. It is crossed by a dyke of olivine basalt, an 
unaltered igneous rock running north-west and south-east, probably 
of Tertiary age, a specimen of which is shown. <A piece of dolo- 
mite, a crystalline limestone from a vein, is shown, and a bit of 
quartzite from a block, none of it seen in situ. From Glas Eilean 
(the grey isle), north of Otter Spit, we show a piece of quartzite 
and two pieces of quartz schist, one of them much folded. The 
two islands opposite Minard Castle, Hilean Aoghainn (lambs’ 
isle) and Fraoch Eilean (heather isle), seem to be composed 
entirely of coarse epidiorite. Most of the upper part of Loch 
Fyne has been hollowed out of the softer rocks of this 
series. 
From the shore, and from the banks of the little burn, to the 
west of Dundarave Castle, on the north-west coast of the loch, 
are exhibited several specimens of quartz-schists with calcareous 
matter in them, one with acute foldings. The knoll on the 
water-edge, near the castle, doubtless the site of the original 
“dun,” or fort, from which is derived the name Dumn-da-raimh 
(rave) =“‘the fort of the two oars,” is composed of fine-grained 
epidiorite, apparently intrusive, a specimen of which is shown. 
The epidiorite, being harder than the surrounding schists of 
sedimentary origin, has resisted denudation better, and so stands 
up as a knoll. 
This knoll and all the islands are more or less smoothed, 
rounded, and grooved by the action of the mass of ice that in the 
glacial period filled up Loch Fyne. The directions of the 
markings run in the line of the loch. 
The “spit” of gravel and shingle at Otter (Gaelic, Ozti, a pro- 
jecting ridge or bank in the sea), which divides Loch Fyne into 
“Upper” and “Lower,” may be a moraine re-assorted by water, 

