504 [P'oc- B.N.F.C, 



opinion that the cement-like matrix binding the irregularly 

 laid boulders together, was nothing more than a natural cal- 

 careous paste, common enough in localities where limestone is 

 the prevailing rock. The huge boulders of basalt on the beach 

 are next visited, and photos of these — perhaps among the 

 largest of the grinding tools of the glacier epoch — are taken. 

 Blackhead, with its caves excavated in the trappean cliff, is 

 another interesting geological lesson. The restless sea makes 

 little inroad on these rocky bulwarks ; here and there, how- 

 ever, vertical rifts are observed along the cliff line, these almost 

 invariably mark the site of an ancient fissure, through which, 

 in a distant past, welled up the lava which formed the upper 

 hands of the Antrim basaltic plateau. They speak of frequent 

 stupendous eruptions extending over vast time. Previous out- 

 flows had solidified, and had perhaps become covered with 

 vegetation, then subsequently rent and fissured and overflowed 

 by succeeding outbursts. The deeply indented caves which 

 now form a striking feature in the Gobbin cliffs, and at Black- 

 head, are carved out of fissures or rents of these later outflows, 

 the softer filling of which has yielded to time and the ocean 

 waves. A scramble over the headland and a leisurely return 

 concluded an instructive afternoon's excursion. 



On loth and nth August, to 



MAGILLIGAN AND LIMAVADY. 



The party reached their destination by means of the Northern 

 Counties Railway ; picking up stray members at various points 

 of the very pleasant journey. At Limavady, all, under the 

 guidanceof a local contingent in the persons of Thomas Fleming, 

 Esq., F.G.S., and the Rev. Canon Ross, proceeded on their tour 

 of exploration, visiting ruins of churches, and other ancient 

 remains in the locality, and then proceeded on foot through 

 Roe Park, exploring the beautiful valley of the Roe, and halting 

 at the celebrated Lim-an-madadh, or " Dog's Leap," discussed 



