The Scottish Naturalist. 93. 



short distance, however, this type disappears, owing to the limited development 

 of the felspar and the greater abundance of the horn blende. In the latter case, 

 the rock approaches the type of amphibolite, and where foliation occurs it might 

 be termed a horn-blende schist. All these varieties are to be found on the shore 

 west of Durn Bay. At various points lenticular patches of quartzite, mica 

 schists, and calcareous bands occur in the midst of the diorite, with the normal 

 strike of metamorphic strata in the neighbourhood. There are no fewer than 

 six veins of serpentine associated with this mass of diorite, two of which are of 

 special interest and importance. Both of them lie to the west of the Battery, 

 the largest occurring at the marble quarry. From these veins excellent speci- 

 mens may be obtained of the green and mottled varieties of serpentine. The 

 joints are usually mottled with steatite, and thin veins of chrysolite of great 

 beauty intersect the rock. In addition to these minerals, asbestos and enstatite 

 have also been met with. The large vein to the west of the Battery displays a 

 gradual passage from the diallage rock or gabbro into serpentine, a graduation 

 which is amply proved by chemical analysis as well as by microsopic examin- 

 ation. On the west side of the marble quarry, the serpentine is bounded by 

 diorite or foliated horn-blendic rock passing downward into chlorite schists* 

 large bomb-shaped masses of diorite are completely enveloped in the soft green 

 chlorite schists. They vary in size from 2 to 5 feet in diameter, and are 

 arranged in a linear manner along the lines of foliation. From the appearances 

 presented by the chlorite schist it is evident that they are the result of the alter- 

 ation of the diorite masses at that locality. Following the shore westwards, we 

 gradually descend through flaggy limestones, argillites, chiastolite slates, mica 

 schists, with actinolke and serieite schists to the quartzitcs of Redhythe Point 

 and Durn Hill. 



Cullen Bay occupies the centre of a synclinal fold in the ancient crystal- 

 line rocks. The fine-grained quartzites and mica schists which dip to the 

 south-east on the cliffs near Cruats, reappear with a north-west inclination to 

 the east of the harbour. The members of this series are the northern prolong- 

 ations of the quartzites on Ben Aigen and the Bin of Cullen, but owing to 

 various foldings, they occupy a large part of the coast section. The Three 

 Kings of Cullen consist of these fine-grained quartzites, which have been brec- 

 ciated by faults running in a north and south direction. On the west side of the 

 bay there is an important outlier of Old Red Sandstone, which exhibits a 

 remarkable instance of double unconformity. At the base, the strata consists 

 of coarse brecciated conglomerates, dipping at a gentle angle to the west of 

 north, and passing underneath friable red sandstones. As we follow the cliffs 

 northwards in the direction of Scar Nose, the basal conglomerates disappear, 

 and the overlying sandstones rest directly on the truncated edges of the 

 quartzites. This outlier must have extended formerly along the valley of the 

 Cullen Burn, because another fragment of this formation is to be found on the 

 right bank of the stream above Cullen House. 



BERWICKSHIRE NATURALISTS' CLUB. 



On 27th July, the second meeting of the season was held, the day being 

 devoted to an excursion to Holy Island. There was a full attendance, repre- 

 sentatives being present from most of the southern counties of Scotland, and 

 also from Durham. The interesting ruins on the island received the attention 

 they merited, while the botany proved of much interest to several members, 

 with the result of yielding the following additions to the recorded flora of the 



