Mr George Logan on Fossil Plants. 367 



according to the way in which the cart was turned in throw- 

 ing them out. The metal upon a macadamised road also 

 shows the same arrangement. 



The currents of the atmosphere likewise exhibit the same 

 phenomenon. As is well known, the storms of southern 

 latitudes revolve from left to right, whilst those north of the 

 Equator revolve in an opposite direction. These revolving 

 storms, to which the term " cyclones" has been applied, 

 appear to be truly of spiral form. This has been all but 

 demonstrated by the able and laborious researches of Mr 

 Buchan, secretary to the Scottish Meteorological Society, 

 (vide his paper in the " Transactions of the Koyal Society 

 of Edinburgh," read 3d April 1865), and will probably be 

 soon placed beyond a doubt. 



It is not the object of this short paper to enter into any 

 investigation as to the exact manner in which the spiral 

 forms in question are produced, but simply to call attention 

 to a subject which seems, so far as the author is aware, to 

 have been overlooked by even the most acute observers of 

 physical phenomena, but the study of which will be found 

 highly interesting as well as instructive. 



(2.) Mr George Logan exhibited specimens of Fossil Plants from 

 the Upper Old Red Sandstone, near Dunse; with Notes by William 

 Stevenson, Esq., Dunse. 



The two specimens of vegetable fossils exhibited are from 

 the Upper Old Eed Sandstone of Prestonhaugh (between 

 two and three miles north of Dunse). In the same beds a 

 fine specimen of the Cyclopteris Hibernica was found a few 

 years ago by Mr Stewart, Edinburgh, who presented it to 

 Hugh Miller, in whose collection I saw it shortly afterwards. 

 Though common in the Irish Devonian strata, I believe 

 that no other specimen has been found in Scotland. In the 

 Prestonhaugh beds are many obscure vegetable remains, ap- 

 parently fucoids, some of large size. Associated with these 

 are remains of the Holoptychius nobilissimus, Pterichihys 

 major, &c, characteristic of the Upper Old Eed. Several 

 of the strata are beautifully rippled, and some show cracks 



