ERRATIC BLOCKS OF THE BRITISH ISLES. 147 
of gravel have been removed, and have revealed many interesting 
mammalian remains, including the bone of a seal, which is the first 
record for that species from the Holderness drifts. 
TRELAND. 
Reported by the Committee of the Geological Section of the Belfast 
Naturalists’ Field Club. 
The Committee record the extension of the area of distribution of 
Ailsa Craig Riebeckite-eurite to Moys, two miles west of the Roe, by 
Madame Christen; the rock has also been found for the first time at 
Limavady, Kilrea, Aghalee, Drumaneway, Dervock, and the White 
Mountain, north of Lisburn; at the latter locality it was found by 
Mr. Robert Bell, at an elevation of 800 feet. 
Dungannon, Tyrone, Brickfield. Brown Boulder-Clay, overlain by 
black Boulder-Clay. Erratics:—Jasper, green rock series of Mid- 
Tyrone—red granite, ironstone nodules, dolomitic limestone, red lime- 
stone, concretionary iron ore, sandstone (probably local)—porphyritic 
syenitic granite, quartz-porphyry, probably Slieve Gallion—quartzite, 
diorite, epidiorite, Dalradian series, chalk, flint, gneiss, basalt, 
Carboniferous conglomerate. 
Portstewart, Sand-hills. Epidiorites, metamorphic grits, granite, 
quartzites, arkose, porphyritic felsite, metamorphic sandstone, 
Dalradian, from Londonderry, Donegal, or Scotland—rhyolite 
(?trachyte), Tertiary series, Antrim—coarse granite, orthoclase rock 
(syenite group), granite-porphyry, syenite, Slieve Gallion, quartzite, 
porphyries—granite, riebeckite rock, Ailsa Craig—schist, altered 
diabase with epidote. 
Limavady, Ballast-Pit near Railway Station. Erratics :—Riebeckite 
rock, Ailsa Craig—gabbro, hypersthenite (Slieve Gallion)}—meta- 
morphosed grit, epidiorites, quartzite, vein quartz—fine gneiss, 
granulite, Tyrone—red granites, hornblende schist—diorite, with 
granular ground. 
Derrybeg Brickfield, Limavady, Boulder-Clay. Erratics :—Meta- 
morphosed grit, Carboniferous sandstones, quartzite, diorite with 
granular ground, mica hornblende-schist, red and pink granites, crushed 
felsite, epidote granite with hornblende. 
Moys, nearly four miles §. of Limavady, Gravel-Pit, Knockandunn. 
Erratics :—Riebeckite rock, Ailsa Craig—fine-grained granite—meta- 
morphosed grits and sandstones, quartzite—pink granite, Carboniferous 
sandstone—gneiss. 
Aghadowey, Gravel-Pit, Clare Hill. Erratics:—Micropegmatitic 
granite, quartz-porphyry, grey granites—crushed granite—quartzite, 
felsite, metamorphosed grit—vein quartz, epidiorite. 
Kilrea Gravel-Pits. Erratics:—Riebeckite rock, Ailsa Craig—red 
and pink granites, green phyllite, rhyolite, diorite, gabbro—red 
Carboniferous limestone—coarse gneiss, dark red granite—quartzite. 
Cavanmore Road, Gravel-Pit three miles from Kilrea. Erratics :— 
Hornblendic granite, quartzites, grey granite, red granites—meta- 
L 2 
