88 Reports and Proceedmgs — 



The paper commenced with a brief outline of the physical features 

 of the basaltic area in Ireland. The beds whence plants have been 

 obtained form a quadrilateral, the angles of which are Ballintoj^, 

 Glenarm, Ballypalady, and Lough Neagh. The Ballintoy beds are 

 very incompletely explored, and have so far yielded few species. '1 he 

 Glenarm beds are situated in a disused mine, filled with water, which 

 was drained by the author. The plants are well preserved in a 

 matrix of white sandy clay. The Ballypalady plants are less perfectly 

 impressed in a matrix of ochreous earth. Many of the plants are 

 common to botli ; but Ballypalady possesses a whole group of 

 conifers, including a cj^press, yew, many pines and firs, not met with 

 elsewhere ; while Glenarm is richer in leafy trees. Among the 

 plants in common are two which still exist, Cryptomeria, and a 

 peculiar Pteris with reticulated venation. Among extinct plants the 

 presence of Macclintockia especially points to their age being the 

 same as the Heersian flora of Gelinden in Belgium, a stage very low 

 in the Eocene, The Lough Neagh beds are estimated to be as much 

 as 500 feet thick, and their flora shows tliem to be interbasaltic, and 

 therefore Eocene instead of Pliocene as hitherto sometimes supposed. 

 The great extent these beds formerly held is shown by the area over 

 which silicified wood derived from them lies scattered. The basalts, 

 here as elsewhere, have been enormously denuded ; and the author 

 believes that the horizon of the Mull leaf-bed is not anywhere 

 present in Ireland. The Mull bed is regarded in this paper as 

 probably of the same age as the Woolwich and Reading series of the 

 London Basin ; it was deposited on the flat banks of a river, liable to 

 inundation ; while the Irish beds, are fluviatile, not lacustrine, with 

 the probable exception of those of Lough Neagh, which may be 

 lacustrine. 



II.— December 14, 1884.— W. Carruthers, Esq., F.E.S., Vice-Pre- 

 sident, in the chair. — The following communications were read : 



1. '' On the South-western Extension of the Clifton Fault." By 

 Prof. C. Lloyd Morgan, F.G.S., Assoc. R.S.M. 



This fault cuts across the strata out of which the Avon gorge has 

 been excavated, a little north of the Suspension Bridge. According 

 to the author's estimate, the throw of the fault is, on the Gloucester- 

 shire bank, somewhat less than 1200 feet, and somewhat more than 

 1100 feet on the Somersetshire bank. The difference of nearly 100 

 feet the author considered to be, in part at least, due to the dying-out 

 of the fault to the west. Taking as a datum-point the intersection of 

 the line of fault and the line of high- water mark, the rocks relatively 

 shifted downwards are, on the Gloucestershire bank. Mountain 

 Limestone 730 feet. Upper Limestone Shales 470 feet. According to 

 this estimate, there would be 130 feet of Upi)er Limestone Sliales 

 above high- water mark, above which beds of Millstone Grit would 

 be brought down. This accords with observed facts. On the 

 Somersetshire bank the beds brought down below high-water mark 

 are Mountain Limestone 770 feet. Upper Limestone Shales 330 feet. 

 According to this estimate, there would be 270 feet of Upper Lime- 

 stone Shales above high- water mark, which would thus leave little 



