368 Geological Society: — On the 



period of general glaciation Shetland nourished a series of local 

 glaciers which radiated from the high grounds, the direction of the 

 striae being at variance with the older system, while the morainic 

 deposits also differ in character from the Boulder- clay produced "by 

 the great Mer de Glace. 



The authors described the order of succession in the Old Red 

 Sandstone formation in Shetland, and referred to the discovery of an 

 abundant series of plant-remains in rocks which have hitherto been 

 regarded as forming part of the series of ancient crystalline rocks. 

 The plant- remains are identical with those found in the Old-Red- 

 Sandstone rocks in Caithness, Orkney, and Shetland, from which it 

 was inferred that the quartzites and shales in which the fossils are 

 imbedded must be classed with this formation. The authors also 

 described the great series of contemporaneous and intrusive igneous 

 rocks of Old-Red-Sandstone age, adducing evidence in proof of the 

 great denudation which has taken place in the members of this for- 

 mation in Shetland. 



3. " On the Southerly Extension of the Hessle Boulder-clay in 

 Lincolnshire." By A. J. Jukes-Browne, Esq., B.A., E.G.S. 



The southern boundary of the Hessle Clay has not hitherto been 

 satisfactorily determined. The author traces this deposit along the 

 border of the flat fen-land in South Lincolnshire, near Burgh, Steeping, 

 &c, and the east and west Pen. He concurs with Mr. Searles 

 "Wood in believing the clay to be the product of shore-ice along a 

 coast-line, and that the materials were in great part derived from 

 the older " Purple Clay." He differs, however, from that author as 

 to the correlation of the Hessle series, thinking this more probably 

 older than the oldest river-gravels of the S.E. of England. In an 

 appendix a deep -well section at Boston is discussed, and reasons are 

 given for assigning the greater part of the beds in this to the Jurassic 

 Clays, not to the Glacial. 



April 9. — Henry Clifton Sorby, Esq., E.R.S., President, in the 



Chair. 



The following communications were read :— 



1. " On the Geological Age of the Rocks of the Southern High- 

 lands of Ireland, generally known as ' the Dingle Beds ' and ' Glen- 

 gariff Grits.' " By Prof. E. Hull, M.A., E.R.S., E.G.S. 



After reviewing the opinions of previous writers with reference 

 to the age of these beds, including those of Hamilton, Griffith, 

 Murchison, Kelly, Jukes, and the Officers of the Survey, which 

 showed that great uncertainty has hitherto prevailed, the author 

 quoted a passage of the late Prof. Jukes in which he confessedly 

 left the determination of the age of these beds open for future 

 examination ; and he therefore determined to reinvestigate the 

 question, bringing to bear upon it the knowledge which had since 

 been acquired of other districts. Eor this purpose (and accom- 

 panied by Messrs. O'Kelly and M 'Henry) he examined a series of 

 sections, from the coast of Dingle southwards to Bantry Bay, and, 



