390 MAJOR A. It. DWERRYHOUSE ON THE [vol. lxxix, 



The Country north of Garvagh. 



On the flanks of Gortnamoya Hill is a thin coating of brown 

 gravelly drift containing basalt, schist, vein-quartz, Tyrone gabbro, 

 and diorite ; and on the col three-quarters of a mile south of 

 Coolnasillagh Bridge similar material occurs in mounds which run 

 north and south. There is no drainage-channel visible on this col, 

 but thick peat is present. 



The great lateral moraine which crosses the Agivey River is 

 continued northwards hy a series of detached drift-mounds of drum- 

 linoid form, as, for instance, that at Hill of Boleram, 3 miles 

 north-west of Garvagh, and that on which stands the Roman 

 Catholic Chapel between Boleram and Lower Belraugh. 



There are wide drainage-channels east and west of the latter 

 hill, both being cut in basalt and falling northwards into the valley 

 of the tributary of the Aghadowey River, which flows under 

 Boleram Bridge. In the Aghadowey River itself, both above and 

 below Shanlongford Bridge, are sections in brown boulder-clay 

 and coarse gravels containing basalt, hornblende-schist, rotten 

 mica-schist (common), vein-quartz, quartzite, red Carboniferous 

 sandstone, red ironstone (Slieve Gallion), and red granite and 

 hornblende-diorite from the Tyrone Axis. Many of these boulders 

 are more than a foot long. 



At Ringsend is a well-marked channel, at 360 feet O.D., cut in 

 basalt and falling northwards, west of the Presbyterian Church, 

 and a smaller one at 450 feet west of Priests Castle. 



Immediately north of Cashel Bridge is a road-cutting in basalt 

 without drift. 



Three Nook Glen is another streamless channel cut in basalt 

 and falling northwards ; it is at a height of 380 feet. A similar 

 channel is seen on the west of the road, having its intake at Leek 

 Orange Hall, at 430 feet ; and another at Lower Cam, half a mile 

 farther west, at 460 feet, both falling northwards into the valley 

 of the Shinny Water. A further channel at 480 feet, at Shinny 

 Bridge, connects the valley of the Shinny Water with that of 

 Roaring Burn, a tributary of the Macosquin River. 



At The Pass, 5 miles west of Coleraine, is a shallow flat-floored 

 valley connecting the valley of the Macosquin River with that of 

 the Articlave River on the north. This is at a height of 370 feet, 

 and is almost level. The floor is flat and swampy, and, although 

 the present diminutive stream flows northwards, it is difficult to say 

 whether the glacial drainage went northwards or southwards. 



The col south of Windy Hill (820 feet O.D.) is cut by a deep 

 channel, which connects the basin of the Macosquin River with 

 that of Lough Foyle on the west. This channel, which is stream- 

 less, is about 35 feet deep, and has a flat floor : it is known as 

 The Murder Hole. The bottom of the channel is practically level, 

 and I am very doubtful as to the direction in which the glacial 

 waters drained. 



Half a mile away to the south is another col in a similar 



