Proceedings. cxv. 



of Northumberland, the scenery along the dyke was most 

 beautiful and picturesque, high precipitous crags with little 

 lakes nestling at their base, and crowned along part of their 

 course by the old Roman wall, in many places very perfect. 



At Bamborough the mass of basalt was about 40 or 50 feet 

 thick. At its opposite extremity where it crosses the head of the 

 Tees, between Durham and Yorkshire, it attained a thickness 

 of about 200 feet. The basaltic dyke was in the whole of its 

 course thrust up through the mountain limestone. Its date 

 appeared to be between the end of the carboniferous period and 

 the beginning of the new red sandstone period, as the latter rocks 

 are never disturbed by it. In addition to this great dyke were 

 others much smaller and more local, and running more or less 

 nearly at right angles to the great dyke ; these mostly occurred 

 in the coal measures of Northumberland and Durham, and 

 produced the disturbances and faults so well known in the 

 working of collieries. 



Wherever the basalt is thrust up through other strata it 

 produces remarkable effects upon them, entirely altering their 

 character. Hence its effect upon the flora of a district is 

 considerable. 



In Northumberland, at Kyloe Crags and elsewhere, several 

 rare and interesting plants are only found, Asplemum 

 septentrionale,Allmin sclioenoprasum,Convallaria verticillahim, 

 amongst others. But it is in Teesdale that its action is most 

 marked, the many very rare and interesting plants found there, 

 growing almost exclusively on the " Sugar" limestone— which 

 is Mountain Limestone metamorphosed by heat, and con- 

 verted into a friable white granular stone, whence its name. _ 



On this formation, three plants, found nowhere else in 

 Britain, grow, viz. : Viola arenaria, Alsine uliginosa, Polygala 

 7</ig-n;osa, besides some others of extreme rarity, e.g. Helian- 

 theniim vineale and Kobresia caricina. 



It is worthy of note also, that the localities for these plants 

 are excessively limited in area ; they are confined each to one 

 spot, and in several cases these spots are inhabited by only 

 one of the plants. 



Reverting to the Fame Islands and the neighbouring main- 

 land, Mr. Mennell referred to their interesting historical 

 associations. Bamborough Castle, built by Ida, king of 

 Northumberland, around which many memories cling, from 

 that early date down to near our own times. Dunstanborough 

 Castle, remarkable for its wild and picturesque situation, which 

 forms one of the finest drawings in Turner's " Liber Studiorum." 

 But it is with legends and stories about Saint Cuthbert 

 that the whole region abounds. The Eider Duck is known as 

 S. Cuthbert's duck. The joints of the fossil encrinites which 



