1820.] ■ Geological Society. 57 



part of the bed is composed, and enclosing angular lumps of 

 black limestone and marine exuvia fossilized by lime. A bed of 

 greenstone in which hornblende is remarkably well crystallized 

 occurs to the south of Port le Murray. 



Fibrous actinolite occurs in two veins near the Dun, traversing 

 the decomposed portion of the granite and gneiss, and veins of 

 chlorite are found in different parts of the island traversing the 

 clay slate, and often colouring the quartz. 



Curragh is a name given to any tract of peat bog. These 

 curraghs exist both in the low lands and on the tops and sides 

 of mountains, and in most of them are found trees often of a 

 considerable magnitude, and principally oak and fir ; hazels also 

 with their nuts are common ; ash and black alder are in some 

 instances met with, and in one of the mountain curraghs, 

 holly has been found. These trees are never even partially 

 charred, but the oak is frequently tinged of a deep black colour, 

 and when properly seasoned will admit a polish equal to ebony. 

 Towards the north, the trees lie in general upon a bed of clay ; 

 in some of the deeper curraghs they are still erect, but for the 

 most part they are broken about two or three feet from the roots. 

 In the parish of Kirk BalafF there is a bed of marl, in which are 

 found the remains of the gigantic elk. Over it is a bed of sand 

 six feet thick, and upon that hes a kind of peat a foot and a half 

 thick, and composed of rotten leaves and small branches closely 

 matted together, and containing a vast number of the exuvia of 

 beetles, bees, and their nests, crushed together. From these 

 appearances it may be inferred that an extensive forest has been 

 overwhelmed by an irruption of the sea bringing with it a large 

 portion of sand. Between 20 and 30 years ago, the sea, during 

 a violent storm, laid bare a forest about midway between high 

 and low water mark in Poolwash Bay. The trees were of the pine 

 tribe, and lay dispersed in the same direction as those before 

 mentioned, viz. from south-west to north-east. 



An appendix to the paper " On the Geological Relations of 

 the Environs of Portrush," by T. Weaver, Esq. containing 

 • " Observations on the Organic Remains in Trap," was read. 



At Portrush, and in the Skerries Island, the kind of trap 

 containing petrefactions of ammonites, pectinites, and belemnites, 

 is evidently a part of that extensive formation which was depo- 

 sited subsequently to chalk, and which reposes principally upon 

 it in the north-east quarter of the island. But detached por- 

 tions of the same formation are also to be found in the country 

 adjacent to the grand deposition, being dispersed over both 

 primary and secondary tracts, and in some cases also covering 

 layers of bituminous wood, and consequently may be considered 

 as belonging to that series which has been denominated the 

 overlying or newest floetz trap formations. 



The rock of Portrush and Skerries has been considered by 

 some geologists as being a flinty slate rather than a basalt, but 



